system won't boot

My system was working fine then in the middle of playing solitare the computer shut down by itself.  WHen I try to reboot it the yellow and green light on the front of the tower stay on and it sounds as if the fan is running.  The monitor comes on for a minute then shuts off.  I am thinking it could be a video card problem but why would both lights be on the tower?  Also the CD drive door doesnt' open so something else is going on not just a monitor problem.  I have a DELL thats only 3 years old and the owners book says it could be a BIOS problem and to try plugging it into a different outlet?  Sounds silly but I did and it still doesn't work.       I am running XP.  Any clues as to what the problem could be?

Lizzy
Crikey, sounds a bit ominous! Don't know, but l would think a 'duff' video card wouldn't stop the cd from opening.
What l would try is -
Disconnect power supply and remove casing.
Remove the battery, check all connections (the wiggle test! ha ha), and if dusty clean it out, then replace the battery and casing and try again.
Regards
WTC

From your complain, it lead my mind to your system memory. If you are comfortable with opening your PC, then you should check your RAM card(s). Remove it from its slot, get dust particles away from the slot and card, insert it back firmly. Then reboot. Goodluck from Ovie aka Trizle1