I mostly mentioned the RAM to emphasize that all non-essential programs should be shut down.
With Beyond Divinity a few people fixed crashes involving slash1.dll by updating to the latest video card drivers, but I don't think Divine Divinity had the same problem.
The topic
Awful Slowdown for BD contains some information on RAM programs and settings. A web search should also come up with a guide for tweaking memory settings in Windows XP.
See also;
Troubleshooting Tips (& manual install procedure) 
