If you have a corrupted account (user profile) where things are all messed up when you login or you can't login then follow the directions here to create a new account and copy all your user data over to it:
http://support.microsoft.com/?kbid=811151
Or follow these directions posted in GeeksToGo.com
- Boot to Safe Mode, login as Administrator
- Show hidden files by opening My Computer, Tools menu, View tab, check Show Hidden Files/Folders and uncheck Hide extensions for known filetypes. Click Apply then OK.
- Create a new Administrator level account via Control Panel / User Accounts.. Pick a good name as you will be keeping it.
- Reboot the computer.
- Login with the new account so the folder structure under Documents and Settings gets created, then log off.
- Boot to Safe Mode, login as Administrator
- Browse to c:\documents and settings\OldUserAccount
- Select everything in that folder except the three files called ntuser.dat, ntuser.dat.log, and ntuser.ini.
- Copy all those files into c:\documents and settings\NewUserAccount. Reply Yes or Yes to all when duplicate folders or files are found.
- Reboot the computer and login with your New user account.