Download CWShredder, HijackThis, CCleaner and the trial versions of CounterSpy and SpySweeper. Update them all, boot into Safe Mode and then run FULL system scans with all of them.
If you don't know what to delete in the HijackThis results list, then post a log, maybe some of us can help you.
If you don't know what to delete in the HijackThis results list, then post a log, maybe some of us can help you.