The first thing you should do If you think your computer has been infected by a virus or spyware is back up all your important documents, pictures, music, emails and your address book. Then at least you know that your data is safely stored before you start removing your unwanted visitor(s).

Now try updating your antivirus software and asking it to scan your computer. If you can't update your antivirus software, or your resident antivirus software finds nothing, try doing an online virus scan. Some effective ones to try include:

Housecall http://housecall.trendmicro.co m/uk,

Bit Defender http://www.bitdefender.com/sca n8/ie.html ,

Kaspersky http://www.kaspersky.com/virus scanner

F-secure http://support.f-secure.com/en u/home/ols.shtml

Go to the website of your choice and follow the onscreen instructions. All will scan your computer and remove any malware (a generic term for viruses, worms, Trojans and spyware) they find.

A word of caution. Never rely on these online virus scans to provide you with ongoing protection. They only work when you connect to their website and ask them to scan your computer. You need to have effective, up to date antivirus software installed on your computer.

Once you have scanned your computer with antivirus software you should run an antispyware scan too. Some of the online virus scans also check your computer for spyware infection. However, it might be worth scanning again with dedicated antispyware software.

If you use Windows XP you can download Windows Defender from the Microsoft website www.microsoft.com . (Windows Defender is included with Windows Vista). Other effective antispyware software you can use includes

Adaware http://www.lavasoftusa.com/pro ducts/ad_aware_free.php.

Spybot S & D, available from http://www.safer-networking.or g/en/index.html

If any of these find an infection it is worth noting down what your computer has become infected with. There are some very pernicious pieces of spyware that are very hard to remove or will reinfect your computer at the slightest opportunity. If you find yourself the victim of one of these, do an internet search for a dedicated removal tool.

Another word of caution. If you search for antispyware software and find one that isn't listed above, search for reviews. Some antispyware software isn't what it claims to be and you can unintentionally make matters worse.

Hopefully by now you will have found the infection and removed it. Do a little housekeeping to tidy up your computer's hard drive. Remove unwanted files and programs. Defrag your hard drive.

To help prevent future infections, make sure you have effective antivirus software on your computer which is updating itself regularly. If you have to pay to renew your subscription make sure you do just that. Antivirus software with an out of date virus database is useless.

If the virus that infected your computer corrupted your antivirus software you may have to uninstall it and reinstall it. Make sure you disconnect your computer from the internet before you uninstall.

Also make sure you have effective antispyware software installed. Windows Defender is proactive and will scan your computer everyday. Adaware and many others are not you will have to update them and scan your computer regularly.

If you use an internet security suite make sure you know exactly what kind of protection it offers. Many now include antispyware protection which updates and scans your computer regularly.

Learn more about this author, Carol Smith.
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