Problems with home computer

I've had a series of serious problems with my home computer, and have managed to get it running again. However, it will only let me on the internet long enough to load a few pages, then craps out on me. It seems I've deleted a file I shouldn't have when whacking the hordes of virii in every conceivable corner. I am using a public terminal to post so people won't think I'm dead, lost interest, or have been kidnapped by Islamo-fascists or neo-nazis.

Fighting computer problems sucks.