There have been a lot of systems hi-jacked by fake anti-virus/anti-spyware/anti-malware programs lately.  You can do a lot to avoid these and other malware. Do not install anything unless it is really needed and is from a trusted source. Use a non-administrator account as your main account.  

Here are some simple rules to follow to keep Windows running smoothly: keep it updated, keep it simple, keep a backup… Keep windows updated. Don’t ignore that little yellow or red shield down by the clock. Install an anti-virus program, keep it updated, and

Spyware causes as many, if not more, problems on computers as viruses do. But spyware can often causes no problems at all (the best spies are the ones you do not see…). Find spyware and get rid of it using a program like Malwarebytes’ Anti-Malware (www.malwarebytes.org) or Ad-Aware (www.lavasoftusa.com). Avoid getting spyware in the first place [...]

A good anti-virus program is still important for keeping Windows computers running smoothly. There are many good ones, but few that offer as much protection as they were able to a few years ago (malware writers have the advantage lately), but NOD32 seems to be one of the best (www.eset.com). And for home users, the [...]

A good anti-virus program is still critical for keeping Windows computers running smoothly. Symantec (www.symantec.com) and CA (www.ca.com) both have good antivirus programs. And for home users, the free version of AVG (free.grisoft.com) is a good way to go. Keep the anti-virus program up to date and it’s real-time scanner will provide a lot of [...]

Spyware causes as many, if not more, problems on computers as viruses do. Find it and get rid of it using a program like Ad-Aware (www.lavasoftusa.com). Avoid getting spyware in the first place by only installing tools and programs from trusted sources, and using a good popup blocker (built-in to Firefox (www.mozilla.org), or via a [...]

The System Restore tool in the System Tools folder of the Accessories group is a great tool for solving odd problems. With it you can restore your system files to a time before problems appeared. But any files you created will stay just as they are… though it is always safer to have a backup!

Setting Automatic Updates (in the Control Panel of Windows 2000 and XP) to Automatic is best for most people. You will still get the occasional update notification down by the clock (usually for updates that have a license agreement), but most updates will install automatically without you having to do anything.

When you run into a weird problem with a computer, unplugging it for a minute (shutting down normally first, of course) will often solve it.