If re-installing Windows didn't help, that seems to point to a hardware problem (especially if Everquest also used to run fine). Are you shutting down all non-essential programs (especially anti-virus) before starting the game? Re-installing Windows from a restore disk/partition can add a lot of stuff back to your startup menu. Did you check Compaq's site for BIOS or chipset driver updates, etc? Have you checked the BIOS settings to see if the amount of shared RAM for the graphics chip, or something, has been changed?
With Beyond Divinity, a few people have had better luck using the third party
Omega Drivers on laptops. Since the game was working fine, though, the drivers are probably not part of the problem.
There are a couple memory testing programs you can try;
Memtest86 or
MS Windows Memory DiagnosticYou could use something like
Sisoft SANDRA to get detailed information about your laptop and do some tests.