I was trying to log off and my computer went to hibernate. I do not know what I hit that made that happen. The problem is that I cannot restart the computer. It's an HP Compaq NX9030. It runs on XP. I've tried holding the power button, removing the battery, checking to see that it is plugged in, touching the touch pad, tapping the space bar and enter key. Any other ideas? Is it serious?

See if this article helps:

http://h10025.www1.hp.com/ewfrf/wc/genericDocument?lc=en&cc=us&docname=bpu00801