JSI Tip 7178. When you press CTRL+ALT+DELETE to unlock Windows XP, it restarts, sometimes with a STOP: 0xC000021a (Fatal System Error)?

The subject behavior will occur if you have the MUI (Multilingual User Interface) pack installed, AND the Language bar is in the upper-left of your screen when you lock your computer by pressing CTRL+ALT+DELETE and Lock Computer.

To workaround this behavior, move the Language to the bottom of your screen before you lock your computer.