What to Do If Your Computer Has a Virus or Trojan Horse

January 18, 2009

in privacy & security

by Tina Gasperson

The Internet can be a dangerous place for a desktop computer. Sometimes it seems as if there are viruses lurking around every virtual corner. The people who write the code that makes these evil programs run are always thinking of new ways to lure us into their cyber clutches. And unfortunately, sometimes we take the bait.

If you’ve been tricked by a nasty little bit of code and your computer looks like it’s down for the count, don’t despair. Most of the time you can fix it by following a few simple steps.

The first thing to do is make sure the System Restore setting is turned off. To do this, click on Help and Support from the Start menu, click on “Undo changes to your computer with System Restore,” then “System Restore Settings,” and then click the checkbox next to “Turn off System Restore on all drives.” It is important not to leave this step out because many viruses and Trojans use the system restore to surreptitiously reinstall themselves. Don’t worry; once you get the virus taken care of you can turn System Restore back on.

The next step is to scan your entire computer with the antivirus program installed on it. If you don’t have one installed, find a good antivirus program and get it running.

Your antivirus program may or may not find anything wrong with your computer, but if it doesn’t, don’t assume you are not infected. Scan your computer with other free tools such as AdAware, Spybot Search & Destroy, or MalwareBytes Anti-Malware. Make sure that the very latest version of Java is installed on your system, since many malware programs take advantage of vulnerabilities in older versions of Java.

If you’d like some outside help with your computer, download and run the system utility called Hijack This. This little application scans your registry and memory to see what rogue programs may be running or what registry changes have been made that could be attributed to viruses or malware. Save the log and upload it to a forum where there are computer experts waiting to help you figure out if you’ve got some rogue code running on your system. If these guys can’t help you, it may be time to simply reinstall Windows.

Tina Gasperson (tinahdee@gmail.com), affectionately known as Computer Lady by her family, has been writing about IT, home computing, and the Internet for more than a decade.