I am using an HP Compaq Presario SR5152NX computer using Windows Vista Home Premium with Service Pack 1. I have set up a new User Profile without administrative privileges. When I try to log in to it my computer logs in then immediately logs out. When I set the privileges to administrative I can log in just fine, make the changes I want and log out. When I change it back to non-administration it goes back to logging in and immediately logging back out again. What would cause this, and how can I make it work correctly? I want to let a friend use my computer but I do not want him to have full admin access.