I had a similar problem tonight with my profile not loading when I re-started the OS. Somehow my admin. account was changed to a guest account and I was essentially locked out from making any system changes. After re-starting in safe mode and removing the UAC feature I ran system restore. Thanks for the system restore option it works ok now, and I did not have to re-install Vista. If anyone has a problem with permissions that may have been changed by a virus or another problem application, use system restore to fix it.