Try this process the next time your computer goes down or when you suspect it may have a virus. You can use "System Restore" to restore your computer to an earlier date when it was working properly. This may save you a trip to the repair shop which will save you a little money. It starts by clicking on the start menu. Follow this flow chart I made up. Hope it helps.
http://i225.photobucket.com/albums/d...temRestore.jpg