I loaded another user's registry file under HKEY_USERS and added a string value at HKEY_USERS\[User'sName]\Microsoft\Windows\CurrentVersion\Explorer\StartupApproved\Run. The value was a path. And that file
is a .bat which let the user log off. I thought it would make the user log off automaticlly when he logged in. When I tried to log in that account, it took a very long time to log in. Then most of the icons on the desktop couldn't show properly. Soon the screen went dark and then lit up again and looped. But my account was fine.
I pressed WIN+L to quit and deleted the string value, the bat file and reboot the computer but that account was still broken. And I didn't make a back up. HELP!