Got a virus, computer acting slow, getting some random error and programs crashing, you want to fix it?  Here is the fix all to everything... REIMAGE IT.

You need to keep your computer backed up!  How can you do this?  If you have a lot of stuff on your computer, I'd recommend purchasing an External hard drive.  You can typically pick up a nice one for around $100, just watch for sales. If you don't have a ton of stuff (5GIGS or Less), and you have high speed interent, I'd recommend livemesh (www.mesh.com).  Free online storage that you can sync between computers, and access from anywhere online.

Got a virus, and want to try to remove it without a restore?  You'll have different techniques depending on how you answer these questions, and how much you're willing to try.  Do you have another computer?
Do you currently have AntiVirus/AntiSpyware software on your computer?

Some extra Virus Scanning Tools....
Trend / Norton / etc...