I am really having a hard time with this one... So your symptoms are;
1) No start bar or task manager
ever?
2) Disappearing and reappearing icons with a faulty user account?
Is it both of those... one of those... neither of those?
Have you tried creating a new user? Can you get to the system restore in vista itself?
Sorry to be of such uselessness... but I can't figure what the actual problem is
crabby