I've now tried installing Expression Studio 3 three times (downloaded via the WebSiteSpark) program. The first two I tried a mounted ISO, and for the third, I wrote the image to CD. With all three, a few seconds after booting, and a BSOD that requires speed-reading to comprehend, the machine restarts, ad infinitum.
I can start in safe mode and do a system restore to a checkpoint created yesterday, before the logged changes for today, which are "Installed DirectX". After the restore, everything is fine.
I'm running XP SP2 on an HP Pavilion dv9205us, but had to cheat and use drivers for another HP, as no XP drivers are available for this one. Any advice on how to diagnose or fix this issue will be greatly appreciated.