Originally Posted by frank200

Sometime between logging in and preparation of desktop your are being hijacked and the username is being changed to temp. Since a temp folder doesn't exist it is assuming you are a new user and hence it prepares a new desktop and new user defaults just as it would for a new user.

Now we checked for corruption in the system with SFC so the only other thing possible from this section of the forum would be to disable your startup items in case a rogue process has attached itself.

Type MSCONFIG in the search area of the start menu. It will appear at the top. Click it. Then click the startup tab. Click disable all. Then reboot.

Of course you know that arepair or clean install of Vista is always an option.