I blew the dust off my tech support hat this weekend. I actually re-built my girlfriends laptop from the ground up, or at least from the operating system up, as it was too virus-ridden to do much else. After the install, all the updates, and adding a few choice programs it runs better than new. (Better, you ask? Yes, because it doesn’t have all the pre-installed test-drive-ware that normally comes on a new machine. And it went from XP Home to XP Professional).
Part II of this was hooking it all up to Open DNS, to protect against many of the sites where malware is acquired. File sharing sites, and the like. Open DNS is a pretty great product, and it’s free here.