Well my personal computer got a pretty bad virus and it wont even let me run a scan to stop it, it shuts down my computer. I don't have anything of importance on there, so is there any way I can completely wipe my system, while keeping my OS. Basically a factory reset?

http://lmgtfy.com/?q=How+to+Reformat+a+PC

I had this happen a while ago. If I may suggest, load up your computer in another temporary OS, like ubuntu, and grabbing whatever you want/can before you wipe. Just start Ubuntu up as a demo, and you can access all your files (albeit only through the file system).

 

Then you won't lose anything.