XP=Ctrl=Alt+?

Greetings all. My computer tends to lock up, not often but sometimes. Ctrl+Alt+Del doesn't get me a reboot. I'm almost sure I saved some information that said with Xp you could hit Ctrl+Alt+Something besides Del to reboot. Can't seem to find that information anywhere on the machine. Any help?

 

 

Search didn't bring up anything and I may be imagining things but I cringe every time I have to hit the power button.

Thank you much.