Win2k pro freezes in UT2k4

This isn't my system, but when UT2k4 is played on it, it freezes just at a random point. Not all the time though, I have no idea what it could be. The fans are clean so it should be getting air.

What are the specs of the system you're having problems with, and has W2K been updated with any SP?

Well it didn't always do it though. Not sure how updated it is.