My (fairly new) laptop (p4, 512mb ram, etc) running Windows XP home sometimes suddenly shuts off while I'm playing games. So far this has only happened either
a) while I'm playing either warcraft 3 or gunbound, or
b) when I try to turn the computer back on within a few minutes of the other situation.
I looked at the Windows application logs, and an event called ESENT comes up saying "wuauclt (some number). The database engine stopped." around the time it crashed.
For the first few times I thought it was overheating, but then it happened after it was off (and upside down and cool to the touch) for a few hours; I turned it on, loaded up Warcraft 3, and within a few minutes (if it matters, I didn't actually play a game; I was only chatting, so there was no intense toll on the processor/video card) it died on me.
When I try to reboot immediately after, it either turns off while Windows is loading or on the logon screen. If I wait a while, it'll load up just fine.
This happened the first time in mid-May; after that it didn't happen again for a few weeks (even though I played frequently), and between yesterday and today it almost always happens within minutes of starting to play. I regularly run antivirus and windows update, and I even tried turning on automatic updates (which didn't help).
(An aside: in March, there was some problem with the motherboard, which was replaced; I don't know if that has anything to do with the problem)
What is wrong, and how can I fix it?
Thank you in advance; any help is very much appreciated.