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Is Your PC Affected by Spyware?

2008-09-03T00:42:00.000-07:00

The main problem that most people notice with either kind of program is that they cause performance issues with their computers. For example, Internet Explorer might not work properly any more, your computer might hang more frequently, or your computer might slow down significantly. Removing spyware successfully is difficult enough to make preventing it in the first place a priority.

Unauthorized adware and spyware usually install on your computer covertly by using one of two methods:

Tricking you into clicking a link that installs it. Links to spyware can be deceptive. For example, a Web site that's trying to push spyware onto your computer might open a window that looks like a Windows dialog box, and then trick you by installing when you click a Cancel button to close the dialog box. Sometimes, spyware pushers will put a fake title bar in an empty window, and then install spyware when you try closing the window.

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Installing freeware that includes it. For example, you might install a free file-sharing program that surreptitiously installs spyware on your computer. File-sharing programs can be a major conveyor of adware.

Once installed, spyware can transmit your personal information and download advertisements 24 hours a day. It can also hijack your browser settings, such as your home page or search page.

Protect against Spyware and Adware

Without help, you have no way to prevent adware or spyware. Old antivirus programs don't even prevent adware, since they didn't consider them viruses or worms. First, you usually give permission to install adware, although you do so unwittingly because adware and spyware pushers are deceptive. Second, adware doesn't behave like a typical virus or worm. They don't usually do actual damage to your computer, other than wrecking its performance, and they don't spread themselves using your address book. (Although some kinds of adware can break your anti-spyware tools.)

Things are changing for the better, though. Most popular antivirus products now include adware and spyware scanning. For example, the latest versions of McAfee VirusScan, Norton AntiVirus 2004, and Trend Micro PC-Cillin 2004 now scan for some adware and spyware.

Also, some Internet service providers (ISPs) are introducing protection from adware and spyware. For example, America Online (AOL) announced in January spyware protection as an enhancement for AOL 9.0 Optimized. EarthLink also provides adware and spyware protection through the latest version of its software. Of course, to take advantage of the built-in protection that antivirus products and ISPs provide, you have to update to the latest versions, and keep the anti-spyware/adware signatures current.

more information

The most powerful anti-virus software

2008-09-02T00:07:00.000-07:00

XRampAV is the most powerful anti-virus software on the market today. It has a 32-bit engine powered by Hauri and runs over 50 percent faster than other leading anti-virus software. XRampAV fully integrates with windows explorer and popular mail programs and provides complete protection for your whole PC. Since it is fully integrated, you can scan individual files, emails or directories on the fly. XRampAV Resident stays in memory and protects you from all viruses, not matter how they try to enter your system - through email, your network, or other devious means. At XRamp Technologies, we have focused not only on the Virus Detection aspects of an anti-virus program, but also on virus removal. For example, almost all leading anti-virus programs require you to download a program, reboot to a command prompt and run their program to remove the Kletz Virus. XRampAV can remove the Kletz virus on the fly, without even a reboot! This and many other examples is why XRampAV is the most powerful and advanced anti-virus software on the market.
http://www.filetransit.com/view.php?id=17415

What is a boot sector virus?

2008-08-26T03:10:00.000-07:00

What is a boot sector virus?
A boot sector virus is one that infects the first sector, i.e. the boot sector, of a floppy disk or hard drive. Boot sector viruses can also infect the MBR. The first PC virus in the wild was Brain, a boot sector virus that exhibited stealth techniques to avoid detection. Brain also changed the volume label of the disk drive.

How to avoid boot sector viruses.
Commonly, infected floppies and subsequent boot sector infections result from "shared" diskettes and pirated software applications. It is relatively easy to avoid boot sector viruses. Most are spread when users inadvertently leave floppy disks in the drive - which happen to be infected with a boot sector virus. The next time they boot up their PC, the virus infects the local drive. Most systems allow users to change the boot sequence so that the system always attempts to boot first from the local hard drive (C:\) or CD-ROM drive.

Disinfecting boot sector viruses.
Boot sector repair is best accomplished by the use of antivirus software. Because some boot sector viruses encrypt the MBR, improper removal can result in a drive that is inaccessible. However, if you are certain the virus has only affected the boot sector and is not an encrypting virus, the DOS SYS command can be used to restore the first sector. Additionally, the DOS LABEL command can be used to restore a damaged volume label and FDISK /MBR will replace the MBR. None of these methods is recommended, however. Antivirus software remains the best tool for cleanly and accuarately removing boot sector viruses with minimal threat to data and files.

Creating a system disk.
When disinfecting a boot sector virus, the system should always be booted from a known clean system disk. On a DOS-based PC, a bootable system disk can be created on a clean system running the exact same version of DOS as the infected PC. From a DOS prompt, type:

SYS C:\ A:\

and press enter. This will copy the system files from the local hard drive (C:\) to the floppy drive (A:\).

If the disk has not been formatted, the use of FORMAT /S will format the disk and transfer the necessary system files. On Windows 3.1x systems, the disk should be created as described above for DOS-based PC's. On Windows 95/98/NT systems, click Start | Settings | Control Panel | Add/Remove Programs and choose the Startup Disk tab. Then click on "Create Disk". Windows 2000 users should insert the Windows 2000 CD-ROM into the CD-ROM drive, click Start | Run and type the name of the drive followed by bootdisk\makeboot a: and then click OK. For example:

d:\bootdisk\makeboot a:

Follow the screen prompts to finish creating the bootable system disk. In all cases, after the creation of the bootable system disk, the disk should be write protected to avoid infection.

More information

Free Virus Removal Tools

2008-08-26T03:02:00.000-07:00

Sure the antivirus vendors want to make money, but if you ever get the chance to meet one of their virus researchers, you'll find their real motivation is to protect users. As corny as that may sound, it's true. That's why when stubborn or fast-spreading infectors are discovered, antivirus vendors release special tools to remove the malware - and give the tools away free. It's no substitute for installed antivirus software, but if you're already infected and in a pinch, it's the next best thing to, well, installed antivirus software.

Create a Free F-Prot Rescue CD - FRISK Software - one of the oldest and most respected antivirus companies (and the secret sauce hidden in a lot of antivirus products being sold under other names)- offers their F-Prot for DOS scanner free for personal use. It's ideal for making a rescue CD so you can scan the system from a clean boot.
McAfee AVERT Stinger - McAfee AVERT Labs offers a handy utility to run in Windows that cleans some of the more common malware.
Microsoft Malicious Software Removal Tool - Microsoft offers a free tool to remove prevalent software active on the system. The tool is offered via Automatic Updates, Windows Updates, and Microsoft Updates, or it can be manually downloaded using the provided link.
Symantec Virus Removal Tools - Antivirus vendor Symantec offers a wide range of free cleaning tools for individual malware removal.
F-Secure Virus Removal Tools - Another good choice for individual malware removal are these free tools from F-Secure.
For a second opinion scan or a not-so-stubborn infector, try one of the Top Online Scanners

http://antivirus.about.com/od/securitytips/a/resources.htm

Virus Detection and Prevention Tips

2008-05-12T02:43:00.000-07:00

Do not open any files attached to an email from an unknown, suspicious or untrustworthy source.
Do not open any files attached to an email unless you know what it is, even if it appears to come from a dear friend or someone you know. Some viruses can replicate themselves and spread through email. Better be safe than sorry and confirm that they really sent it.
Do not open any files attached to an email if the subject line is questionable or unexpected. If the need to do so is there always save the file to your hard drive before doing so.
Delete chain emails and junk email. Do not forward or reply to any to them. These types of email are considered spam, which is unsolicited, intrusive mail that clogs up the network.
Do not download any files from strangers.
Exercise caution when downloading files from the Internet. Ensure that the source is a legitimate and reputable one. Verify that an anti-virus program checks the files on the download site. If you're uncertain, don't download the file at all or download the file to a floppy and test it with your own anti-virus software.
Update your anti-virus software regularly. Over 500 viruses are discovered each month, so you'll want to be protected. These updates should be at the least the products virus signature files. You may also need to update the product's scanning engine as well.
Back up your files on a regular basis. If a virus destroys your files, at least you can replace them with your back-up copy. You should store your backup copy in a separate location from your work files, one that is preferably not on your computer.
When in doubt, always err on the side of caution and do not open, download, or execute any files or email attachments. Not executing is the more important of these caveats. Check with your product vendors for updates which include those for your operating system web browser, and email. One example is the security site section of Microsoft located at http://www.microsoft.com/security.
If you are in doubt about any potential virus-related situation you find yourself in, you may report a virus to our virus team.

Norton Antivirus 2008 Review

2008-05-08T03:15:00.000-07:00

When the Norton 360 program came out, the concept was conceived that security for the personal computer and the user was initially the first and foremost priority to the creators. With this set of basic tools, the reality of real protection to those who used this software was obvious and some don't know how they ever went on the Internet highway without it installed to begin with. Of course Microsoft has something to do with the Norton 360 and it was a huge step in the right direction for all those involved in the security of the technology world, as we know it. Not only did it give users tools to obtain security on their personal computer but also in a sense the user could actually not have the worry of a invasion of personal privacy. People who have used the older versions of the software thought that the programs made their computer hard drive run sluggish and not want to run to the performance they should be running. However updated and improved those who used the program in the past are not ecstatic about the new program and all that it has to offer. By splitting the initial interface of the program into smaller categories the big problems with the other designs were put to rest, leaving reassurance and the protection of security and the use of fire walling instead. Being able to see different parts of your computer and addressing issues that seem to have a conflict or problem is much easier to fix and correct the problem. And you can also get reports of the scans or other items that go with the program. As you choose the tools and receive the basic scan reports you are able to see the area that is making your computer run slowly or if there's a security problem you can be informed as well. You are allowed to do several things with the Norton software and initially keep your personal computer clean and safe from viruses, Trojans, and so much more. This in the long-term sense of thought will save the user a lot of grief and misfortune of all the problems those without some form of security software on their computer would have. Sadly enough, there are many programs that are downloaded onto computers today that are ultimately attached as Trojans which will literally copy and correspond back giving any personal information you might have stored on your computer. And, once it is attached in most scenarios it is very hard to get the problems uninstalled or deleted from your computer system. Even system restore in most cases will not work; this is why a security program is as important to you as a user. There are several security programs available, however there are only a few that actually do what they are intended to accomplish and it is imperative that the security programs are useful or they will just take up space on your computer hard drive and not do the work it was intended to do. Being prepared and have security on your computer is important to everyone today.

Parent's Guide to Online Chatting

2008-04-15T03:12:00.000-07:00

Internet chatting and text messaging uses its own words and abbreviations. Treat it like a foreign language and learn what your child is saying.Learn the Language:2B or not 2B = To Be or Not To Be

2G2BT = To Good To Be True
411 = Info
4EAE = For Ever and Ever
4EVER = For Ever
4NR = Foreigner
A/S/L = Age, Sex, Location
AAF = As A Friend
AAK = Asleep At Keyboard
AAMOF = As A Matter Of Fact
AAR8 = At Any Rate
ABT2 = About To
ADR = Address
AKA = Also Known As
B4 = Before
B4N = Bye For Now
B4UKI = Before You Know It BB = Be Back
B4YKI = Before You Know It
BC = Because
BFF = Best Friends Forever
BI BI = Bye Bye
BKA = Better Known As
BRB = Be Right Back
BTW = By The Way
C/S = Change of Subject
CWYL = Chat With You Later
CYA = See You
CYT or SYT = See You Tomorrow
Dys = this
FYI = For Your Information
G2G = Got To Go
H/P = Hold Please J5M = Just 5 Minutes
HAK = Hugs and Kisses
HBU = How Bout You
J/K = Just Kidding
KEWL = Cool
KOTL = Kiss On the Lips
L8R = Later
LMIRL = Let's Meet In Real Life
LMK = Let Me Know
LOL = Laugh Out Loud
Lyk = Like
M or F = Male or Female
NALOPK = Not A Lot of People Know
N-A-Y-L = In A While
NEWAY = Anyway
NW = No Way
OMG = Oh My GOD
OTP = On the Phone
P911 = Parent Alert
PIR = Parent in Room
POS = Parent Over Shoulder
QT = Cutie
ROTF = Rolling On the Floor
RU = Are You?
RUOK = Are You Ok?
S or G = Straight or Gay
SWDYT = So What Do You Think?
TDTM = Talk Dirty To Me
THX = Thanks
TMI = Too Much Information
TOM = Tomorrow
TTYL = Talk To You Later
WT = what the
WTG = Way to Go WYCM = Will You Call Me

Microsoft's New Antivirus Alliance

2008-03-30T22:24:00.000-07:00

VIA (Virus Information Alliance)
On Monday, May 19 Microsoft announced a new partnership with two of the biggest antivirus software vendors in the market- Network Associates (makers of McAfee VirusScan) and Trend Micro (makers of PC-Cillin). The alliance, dubbed the Virus Information Alliance (VIA) will actually consist of the research labs from each of those firms- AVERT (Anti-Virus Emergency Response Team) and TrendLabs respectively.
The goal of the alliance is to share and collaborate on new virus, worm and other malicious code threats.

The collective research will be used to form a thorough assessment of the malicious code and the details will be shared with Microsoft customers through a web page (Microsoft Virus Protection Strategies).
Having looked at that web page as it stands now, it could use some more timely information. It has a good amount of relevant data and information in general including tools, how-to’s, links to outside resources and mailing lists for further information and documents such as security best practices users should follow. In the Virus Information section however, Slammer is the most recent threat they have any information posted on. Slammer occurred at the end of January and there have been many new threats since then that users need to be aware of. Just in the past couple weeks there have been two rapidly spreading threats- Fizzer and Palyh. Palyh even masquerades as a bulletin from support@microsoft.com which is all the more reason they should have data about this threat posted to their “Virus Protection Strategies” site.
The downside unfortunately is that the users who need this information the most will never see this site. They will never read this article. The home users with their always-on 24/7 broadband connection to the Internet don’t know what they don’t know. They don’t know enough to realize they need to be diligent about security and that they need to research and find sites like these to provide them the information they need. They think if you have antivirus software installed at all they should be fine. They don’t know that they have to update the antivirus software weekly to stay current with the new threats. They don’t know that viruses are only one problem and antivirus software is only one solution. The first step in having home users become more secure is to have them realize that the responsibility for securing and maintaining the security of their computer lies solely with them.
Sadly, if users knew this stuff and knew that they needed to stay informed they would probably already be receiving email bulletins from Trend Micro or Network Associates when new threats are discovered and won’t need a resource like this one. Those who know they need this information are already getting it elsewhere and those that don’t know they need this information won’t know how to find this Technet web site. Hopefully information coming from Microsoft directly will carry more weight with the home user market and they will take action, but it remains to be seen how Microsoft plans to get the horse to the trough in the first place.

Before you download files, help protect your computer

2008-03-11T02:20:00.001-07:00

Downloading files can include installing programs from a CD, opening pictures or links to Web sites from e-mail, copying Word documents and Excel spreadsheets from the company network, upgrading software acquired from the Web, or transferring music files from a computer half a world away.
Files you download could be just what you expect, but they might also be a vehicle for malevolent intent. Malicious software (also called malware) is software that can harm you or your computer; it can include viruses, worms, spyware, and other unwanted programs.
Before you download files, make sure you are as protected from unwanted software as you can be.
Keep your software safety net up-to-date

Update Windows automatically. If you use Windows Vista, Windows XP, Windows 2000 Service Pack (SP3) or later, or Windows Millenium Edition (Me), Automatic Updates delivers updates to your computer automatically, so that's the easiest and most reliable way to make sure that you get new security and other high-priority updates as soon as they become available. To turn on Automatic Updates, visit Microsoft Update.
If you use Windows 2000 SP2 or earlier, Windows 98, Windows 95, or Windows NT Workstation 4 you can go to Windows Update for the latest security updates. (Make sure to return regularly.)

Regularly download the latest antispyware and antivirus updates, and then scan your computer right away. To do this, subscribe to the program's update service. You can set most of these programs to actively-even automatically-monitor for and help stop spyware and virus intrusions. If you use Windows Live OneCare or Windows Defender for Windows Vista and Windows XP SP2, you can get updates automatically through Microsoft Update.
Improve your computer's overall security

Lay the protective groundwork. Use a firewall, keep your operating system updated with the latest security updates, and use both antivirus and antispyware programs. Learn more about how to better protect your computer.

Set your antivirus program to scan all incoming files and e-mail attachments before you open them. This is different for every antivirus program, so consult the manual or online Help for instructions. If you use Windows Live OneCare you can sign up for Automatic Updates through Microsoft Update.

Use a spam filter. Many e-mail programs offer filters that can help block unwanted messages. Microsoft Outlook has strong natural defenses against junk e-mail, but you can also step up your defense against spam.

Install and run a program to help detect and remove spyware. Some Internet Service Providers (ISPs) include antispyware software as part of their service. If your ISP doesn't offer this, consider Windows Defender. Windows Defender comes with Windows Vista. If you use Windows XP SP2, you can download Windows Defender for no charge.

More ways to protect your computer

2008-03-09T23:44:00.000-07:00

Limited User accounts help protect your Windows XP computer when you surf
It's simple to set up multiple accounts on your computer. And it's wise to avoid surfing the Internet from an administrator account.

Browser hijacking: Help avoid it and undo damage
Help protect your Internet browser and regain control over what you do and see online.

Disable unwanted programs with Windows Vista or Windows XP SP 2
If you've downloaded a program that you don't want, here are some ways to remove it.

5 steps to help protect your computer before you go online
Help secure your computer against viruses, hackers, spyware, and other Internet threats.

Improve the safety of your browsing and e-mail activities
Use high-level security settings, designate trusted Web sites, read e-mail in plain text format, and use a pop-up blocker to maximize your safety online.

How to tell which version you are running
If you are not sure which software version you are running, or even if you have the software installed, here's how to check.

Find tools you can use to remove unwanted software
Download detection and removal tools provided by Microsoft and other companies.

Protect your computer from counterfeit software
To help make sure your software is genuine, validate your copy of Microsoft Windows today.

For Details http://www.microsoft.com/protect/computer/advanced/default.mspx

Antivirus

2008-02-16T21:40:00.000-08:00

Anti-virus software can identify and block many viruses before they can infect your computer. Once you install anti-virus software, it is important to keep it up to date.

What does anti-virus software do?
Although details may vary between packages, anti-virus software scans files or your computer's memory for certain patterns that may indicate an infection. The patterns it looks for are based on the signatures, or definitions, of known viruses. Virus authors are continually releasing new and updated viruses, so it is important that you have the latest definitions installed on your computer. Once you have installed an anti-virus package, you should scan your entire computer periodically.
* Automatic scans - Depending what software you choose, you may be able to configure it to automatically scan specific files or directories and prompt you at set intervals to perform complete scans.
* Manual scans - It is also a good idea to manually scan files you receive from an outside source before opening them. This includes:
* Saving and scanning email attachments or web downloads rather than selecting the option to open them directly from the source
* Scanning floppy disks, CDs, or DVDs for viruses before opening any of the files

What happens if the software finds a virus?
Each package has its own method of response when it locates a virus, and the response may differ according to whether the software locates the virus during an automatic or a manual scan.
Sometimes, the software will produce a dialog box alerting you that it has found a virus and asking whether you want it to "clean" the file (to remove the virus). In other cases, the software may attempt to remove the virus without asking you first. When you select an anti-virus package, familiarize yourself with its features so you know what to expect.

Which software should you use?
There are many vendors who produce anti-virus software, and deciding which one to choose can be confusing. All anti-virus software performs the same function, so your decision may be driven by recommendations, particular features, availability, or price. See the references section for a link to a list of some anti-virus vendors. Installing any anti-virus software, regardless of which package you choose, increases your level of protection. Be careful, though, of email messages claiming to include anti-virus software. Some recent viruses arrive as an email supposedly from your ISP's technical support department, containing an attachment that claims to be anti-virus software. However, the attachment itself is in fact a virus, so you could become infected by opening it.

How do you get the current virus information?
This process may differ depending what product you choose, so find out what your anti-virus software requires.
Many anti-virus packages include an option to automatically receive updated virus definitions. Because new information is added frequently, it is a good idea to take advantage of this option. Resist believing email chain letters that claim that a well-known anti-virus vendor has recently detected the "worst virus in history" that will destroy your computer's hard drive. These emails are usually hoaxes. You can confirm virus information through your anti-virus vendor or through resources offered by other anti-virus vendors.
While installing anti-virus software is one of the easiest and most effective ways to protect your computer, it has its limitations. Because it relies on signatures, anti-virus software can only detect viruses that have signatures installed on your computer, so it is important to keep these signatures up to date. You will still be susceptible to viruses that circulate before the anti-virus vendors add their signatures, so continue to take other safety

Related articles...

For information about potential threats from different Computer Viruses, Worms, Trojan Horses etc and how to avoid, minimize or recover from the damage caused, please read the Sep, 2004 issue of our Monthly Newsletter.
For information on latest virus threats and some helpful links, please log on to Virus Info page of our website .
To download latest virus definitions, Virus Removal Tools and free Anti-virus softwares, please visit our Download Page .

Source: Compiled from online sources.

Note: WorldLink has made every possible effort to ensure that the information contained in the article above is correct. However, we do not accept any responsibility whatsoever for any damage caused by the application of the information contained herein.

article from www.worldlink.com.np

General tips on avoiding Virus Infections

2008-02-06T00:26:00.000-08:00

The following are some good ways of stopping your computer from getting a computer virus infection:

Turn off the feature that allows automatic opening of email attachments, never open attachments from unidentified sources or attachments you are not expecting.
Always scan diskettes, CD's and any other removable media before using them.
Always scan files downloaded from the Internet before using them
Do not install any unapproved software on your computer.
Make sure that your virus pattern files are updated.
Make sure that your computer is patched with the latest security updates.
Scan your computer on a habitual basis

Protect your "Computer's System" From Virus

2008-02-05T23:57:00.000-08:00

Use 7 Tips

i) Use virus protection software: We recommend the use of anti-virus software on all Internet-connected computers. Be sure to keep your anti-virus software up-to-date. Many anti-virus packages support automatic updates of virus definitions. We recommend the use of these automatic updates when available.

ii) Use a firewall: We strongly recommend the use of some type of firewall product, such as a network appliance or a personal firewall software package. Intruders are constantly scanning home user systems for known vulnerabilities. Network firewalls (whether software or hardware-based) can provide some degree of protection against these attacks. However, no firewall can detect or stop all attacks, so it’s not sufficient to install a firewall and then ignore all other security measures.

iii) Don’t open unknown email attachments: Before opening any email attachments, be sure you know the source of the attachment. It is not enough that the mail originated from an address you recognize. The Melissa virus spread precisely because it originated from a familiar address. Malicious code might be distributed in amusing or enticing programs. If you must open an attachment before you can verify the source, we suggest the following procedure:
make sure your virus definitions are up-to-date (see "Use virus protection software" above)
save the file to your hard disk
scan the file using your antivirus software
open the file
For additional protection, you can disconnect your computer's network connection before opening the file. Following these steps will reduce, but not wholly eliminate, the chance that any malicious code contained in the attachment might spread from your computer to others.

iv) Don’t run programs of unknown origin: Never run a program unless you know it to be authored by a person or company that you trust. Also, don't send programs of unknown origin to your friends or coworkers simply because they are amusing -- they might contain a Trojan horse program. v) Keep all applications (including your operating system) patched: Vendors will usually release patches for their software when a vulnerability has been discovered. Most product documentation offers a method to get updates and patches. You should be able to obtain updates from the vendor's web site. Read the manuals or browse the vendor's web site for more information.
Some applications will automatically check for available updates, and many vendors offer automatic notification of updates via a mailing list. Look on your vendor's web site for information about automatic notification. If no mailing list or other automated notification mechanism is offered you may need to check periodically for updates.

vi) Make regular backups of critical data: Keep a copy of important files on removable media such as ZIP disks or recordable CD-ROM disks (CD-R or CD-RW disks). Use software backup tools if available, and store the backup disks somewhere away from the computer.

vii) Disable scripting features in email programs: Because many email programs use the same code as web browsers to display HTML, vulnerabilities that affect ActiveX, Java, and JavaScript are often applicable to email as well as web pages. Therefore, in addition to disabling scripting features in web browsers (see "Disable Java, JavaScript, and ActiveX if possible", above), we recommend that users also disable these features in their email programs.

viii) Turn off your computer or disconnect from the network when not in use: Turn off your computer or disconnect its Ethernet interface when you are not using it. An intruder cannot attack your computer if it is powered off or otherwise completely disconnected from the network.

worldlink.com.np

http://homejob.justfree.com some adsense tips

Wireless Networking

2008-01-01T22:26:00.000-08:00

Wireless networking technologies take the concept of "no new wires" one step further. In a wireless network, all of the computers in your home broadcast their information to one another using radio signals. This can make networking extremely easy, especially if you have computers all over your house. It also makes it a whole lot simpler to move computers around. For example, a laptop with a wireless network card is completely portable throughout the house!

In How Power-line Networking Works, we discussed peer-to-peer and client/server networks. In wireless networking, a peer-to-peer (or point-to-point) wireless network means that each computer can communicate directly with every other computer on the network. But some wireless networks are client/server. They have an access point, which is a wired controller that receives and transmits data to the wireless adapters installed in each computer.

There are four types of wireless networks, ranging from slow and inexpensive to fast and expensive:

Bluetooth
IrDA
HomeRF (SWAP)
WECA (Wi-Fi)

Bluetooth is not widely available yet and is not expected to replace the need for high-speed data networks between computers. You can read more about this cutting-edge technology in How Bluetooth Short Range Radio Systems Works.

IrDA (Infrared Data Association) is a standard for devices to communicate using infrared light pulses. This is how remote controls operate, and the fact that all remotes use this standard allows a remote from one manufacturer to control a device from another manufacturer. Since IrDA devices use infrared light, they depend on being in direct line of sight with each other. Although you can purchase and install an IrDA-based network capable of transmitting data at speeds up to 4 megabits per second (Mbps), the requirement for line of sight means that you would need an access point in each room, limiting the usefulness of an IrDA network in a typical home layout.

Before we talk about SWAP and Wi-Fi, we need to understand the original standard that both of these new specifications are based on. The original Institute of Electrical and Electronics Engineers wireless-Ethernet specification, known as IEEE 802.11, designated two ways of communicating between devices and allowed for speeds up to 2 Mbps. Both communication methods, direct-sequence spread spectrum (DSSS) and frequency-hopping spread spectrum (FHSS), use the frequency-shift keying (FSK) technology we discussed in power-line networking. Also, both are based on spread-spectrum radio waves in the 2.4-gigahertz (GHz) range.

Spread spectrum simply means that data is sent in small pieces over a number of the discrete frequencies available for use at any time in the specified range. Devices using direct-sequence spread spectrum (DSSS) communicate by splitting each byte of data into several parts and sending them concurrently on different frequencies. DSSS uses a lot of the available bandwidth, about 22 megahertz (MHz). Devices using frequency-hopping spread spectrum (FHSS) send a short burst of data, shift frequencies (hop) and then send another short burst. Since the FHSS devices that are communicating agree on which frequencies to hop to, and use each frequency for a brief period of time (less than 400 milliseconds) before moving on, several independent FHSS networks can exist in the same physical area without interfering with each other. Also, due to FCC restrictions, as well as the fact that FHSS devices generally send data on just two to four frequencies simultaneously, they only use 1 MHz or less of the available bandwidth. Because they use any given frequency for such a short time, FHSS devices are less prone to interference than DSSS devices. But DSSS is capable of much greater speed than FHSS since these devices can send a lot more data at the same time. Currently, FHSS-based devices are easier and cheaper to produce, which has led the HomeRF group to adopt FHSS as the method of communication for their products.

GET FREE ANTIVIRUS

2007-12-31T21:50:00.000-08:00

Comodo Antivirus

Comodo Antivirus provides real-time scanning, where it resides in memory and checks your programs for viruses as they are run, as well as on-demand scanning for viruses. You can also schedule your scans. It automatically updates itself through the internet. Note that you have to activate your copy as well as supply your email address to get and use this software.

Clam AntiVirus

ClamAV is a free command line antivirus scanner for Unix systems. You can also integrate it with your mail server for scanning your email messages and attachments. It is able to scan inside archives like RAR archives, Zip archives, Gzip and Bzip2 archives (that is, it has unpacking engines for those types of compressed archives). If you are a programmer, you can even integrate the antivirus scanner into your own programs. This free antivirus program comes with source code that is released under the GNU General Public License. Prebuilt binary packages are available for numerous Linux distributions (Debian, RedHat / Fedora, PLD Linux, Mandrake), Microsoft Windows, FreeBSD, OpenBSD, AIX, OSF and Solaris 8 (Sparc).

AntiVir Personal Edition

AntiVir Personal Edition is a free antivirus program for Windows computers. It has a resident component that monitors file movements for signs of viruses. It also allows you to scan your computer and repair files that have been infected. The program comes with a facility to automatically check the AntiVir website for updates to the virus definitions and download them. Updates are free.

AVG Anti-Virus

The AVG Anti-Virus software comprises a resident program that works in the background, an email scanner (checks your email for viruses), an on-demand scanner (eg, you invoke it to scan your system), the ability to repair certain infected files, and automatic updates of the virus definitions.

F-Prot Antivirus for Linux, FreeBSD, OpenBSD, NetBSD and DOS

F-Prot Antivirus for DOS, Linux and BSD (FreeBSD, OpenBSD and NetBSD) is free for personal use on personal workstations. (Note: these are separate downloads; scroll down on their page to find the link appropriate for your system. Also note that the Windows and Solaris versions are not free.)

avast! Home Edition

avast! Home Edition is free for home users on non-commercial computers. You have to register your copy and supply them your email address so that they can send you a license key to activate the program.

BitDefender Free Edition

BitDefender Free Edition is a free antivirus program that includes on demand scanning, scheduled scanning, automatic and manual updates of antivirus definitions, etc. There appear to be versions available for Windows, MSDOS, Linux, Windows CE, and Palm.