Have just been removing Fake Anti virus from a clients PC.
Found this on You tube, worked like a dream
I used the "RogueKiller" software in safe mode, it removed the startup files for the "system Tools" fake av.
I then ran my antivirus to make sure that the system was clean. I have had the pc running for a while and used IE and still no fake AV.
Roguekiller - http://www.sur-la-toile.com/RogueKiller/