Since I don't know much about GW or Creative Audigy, the "outside the box" thought is that you may not have kept your AV scans current during your recent OS troubles(?).

There are a number of virus forms, mostly Trojans, that will force reboots at various (and always inconvenient) times. The search string "force reboot" at Symantec security returns a couple of thousand hits.

Your problem is more likely related to "real" software setup, but checking for clean virus condition on the problem machine is fairly simple, and will eliminate at least one thing to worry over.

The second thing to look at is whether you have "system appropriate" drivers on the Win98SE machine. Some download sites check, or ask for, the OS in use, and will download only the drivers for the system on the receiving machine. This can save a lot of download time, but makes the downloaded "version" somewhat OS-specific. If you downloaded GW5 to the Win2K (or some other) machine, it may not have sent you all the "best" Win98SE drivers, even though it looks like you got a good install when you moved it to the other machine. It's pretty easy for tech support people to "forget" that downloaded updates may be OS specific - after all, they've got the full CD installation on their machines.

Both of these things are sort of "shot in the dark" possibilities, but neither should be too hard to eliminate - you may already have the answers on them.

John