Why does Battlefront 2 keep crashing to a blue screen

I have a Windows XP Hewlett-Packard laptop with about 1GB of RAM (it's a fairly old laptop). I ran the diagnostics to see if SWB2 was supported, and it was. Every test passed.
Anyway, I was playing Battlefront 2 two days ago, and during the Mustafar mission on Campaign, my laptop went to a blue screen and restarted after about half a second. This has happened to me 9 times in 3 days, and only on that mission. I've tried changing the priority of the game up and down, turning the graphics up and down, defragmenting the computer-but nothing works. Can someone tell me why? It occasionally bluescreens normally while I'm playing, but never with this much consistency and never so often.