What you may not know is what to do about it. Trying to cure an already infected PC is quite literally like trying to close the barn door after the horses have run out.
Fortunately, there's a new weapon at your disposal: AVG Rescue CD can remove viruses, spyware, and other malware from infected PCs. It's a free, effective, and potentially life-saving tool -- but there's one catch.
The catch: You need to create your rescue CD before your system gets infected. If you wait until after the fact, your system will probably be too choked with malware to perform the setup. So think of this as stockpiling a flu vaccine.
As its name implies, AVG Rescue CD is a bootable CD that employs Linux for its operations, meaning it doesn't boot into Windows (which is where the problems lie, natch). It's also available for USB flash drives, which is my preferred method of deploying the tool -- as long as the infected system supports booting from flash drives, which most modern PCs do. (The software itself requires only about 70MB of space, so even an old 128MB drive will suffice.)
Don't worry about out-of-date virus definitions: The software will leverage your PC's Internet connection to retrieve the latest updates.
I can't say AVG Rescue CD is the most user-friendly tool I've used, so it behooves novice users to watch AVG's two tutorial videos: One on creating a bootable CD or USB drive, the other on using Rescue CD to remove infections from a PC.
I also can't promise that the software will rescue every PC from every infection -- but it's something every user should keep in his or her toolkit. AVG Rescue CD is free; it works with most versions of Windows. [via AppScout]