I have had similar issues but not quite the same.
It was down to a thing called tattooing, which normally gives you grief in a enterprise environment where someone has been fiddling with policy's and profiles in an old NT environment. The user logs in and drags all their local administrators bad habits over onto your network.
It gives no amount of grief when they do it and if you can find a way of reversing it your a better man than me. Spent a day comparing registry's of a before and after image and still couldn't strip it out. Bloody thing stays with the machine and contaminates anyone else that logs onto it.
It sounds like the virus has done some proper damage I would go with a wipe and install as well. I would also make sure that what ever you back your files up onto is formatted using FAT16 or FAT32 and not NTFS. Don't ask why because I don't have a clue for a technical reason just have had issues with "where they hell has it got that from again" which stripping it of all its NTFS extras has solved.
Standing by for your talking bollocks as usual.
You could try creating a new account and seeing if it has the same issues. Even if it doesn't my vote is still to go with a wipe and reinstall.