Now that your computer is all cleaned up and working make a new restore disk. So in the future when this happens and it will, you can just boot from the disk and replace corrupted files.

About once a year i do a low level format on my computers. It makes the hard drive look like it just came off the assembly line. I think it writes zeros to the disk. That way you know for sure that all info is removed. After the reinstallation of windows i just reinstall all my junk from my back up drive.