You could try running regedit in safe made..... You'll need to reboot the pc and press F8 before you see the windows logo and select 'safe mode' or you can somtimes get to the same menu by pressing and holding the Ctrl button until you are presented with a list of windows start options, top one being safe mode. This needs to be done when you first turn on the PC and POST has completed (the bios bit)........
You should also run the ativirus scan in safe mode as well, for a thorough clean and best resaults.
Hope this helps!