Check your add/remove programs for any entries you don't recognise and remove them. Do this in Safe Mode.

Load up Task Manager and see what processes are running and kill them, see if they come back automatically. If so, make a note of them, search the web (on another PC) and look for cleaning instructions.

Do this first and then post the results and the filename, maybe we can get rid of the little bugger.

Cheers

Matt