Alright well my normal measures: Format C:\ won't work this time. They need to keep their stuff, anyway, here is the problem.

They boot into anyones name and the loading user settings crap comes up and then just kicks them back out to logon screen, seeing as I have no physical access to the machine I am just wondering if any of you have experienced such an error and what you did to rectify it.

My immediate thought to fix it was, seeing as its XP, to boot into safe mode and get a system restore point. Which I am having them try at this moment =)