Definitely keep that computer off the internet until you solve this because your friends will not thank you for infecting them -- and your ISP may cut your service unless you wipe the hard drive.
Using another computer download a program that will detect what's running or starting up automatically on your computer -- EasyCleaner is a general purpose program that comes to mind but there are more specialist ones aimed at spotting malware.
Once you have the name of rogue files which are loading Google the names and see what help comes up -- often you'll find specific advice on how to disable and remove particular strains.