I've got a P4P800 Deluxe + CT-479 adapter + Pentium M 730 Dothan + 1GB memory.

I'm trying to run Windows 98SE on it. It seems to run fine for about an hour or so, then a Blue Screen.

I'm not overclocking it at all.

It runs incredibly cool so I'm positive it's not an overheating problem. I even added an extra fan pointed at the CPU and northbridge heatsinks just in case.

I've run the Windows Memory Diagnostic boot disk for about 2 hours and the memory comes up clean.

Just sitting idle it eventually bluescreens.

The blue screen doesn't indicate any particular program or driver either which is the weird part so I'm not really sure how to troubleshoot this.

I'm running the Unofficial Windows 98SE Service Pack 2.

I'm thinking about doing the 98SE2ME upgrade to see if that makes any difference.

Can anyone offer any guidance here?

What's the BSOD message, and is it the same every time?

This is what it was the last time...

A Fatal Exception 0E Has Occurred at 0028:F000EEF3

I believe it's always the same up to the colon but the address at the end might be different. I didn't write them all down.

I tried to install 98SE2ME and it didn't make any difference except the CPU load kept fluctuating between 0 and 100% when running Prime95 torture test, which it didn't do under plain 98SE.

After 98SE2ME didn't work, I gave up and installed Windows 2000 with Gurglemeyer's Unofficial Service Pack 5 slipstreamed in.

I ran the Prime95 torture test last night for over 8 hours and it didn't bluescreen so the problem is definitely Windows 9x and/or one of the drivers.

I think I'll experiment and do a clean 98 install straight from the CD and then try running the prime95 torture test before installing any other drivers or updates. If that passes, I'll add one driver/update at a time followed by prime95 until I figure out what's causing the crash.

AH, you have 1 gig of RAM on the ASUS P4P800 Deluxe mobo? that could be the reason why you are getting those BSOD messages under Win98se. see MS article 253912 on what to do when using 512Mb of RAM or more:
http://support.microsoft.com/kb/253912/en-us

better yet, see this thread:
http://www.msfn.org/board/index.php?showtopic=79756

Yeah, I know. I was one of the posters in that thread. I'm well aware of the memory limitations in Windows 98SE. I'm running the Unofficial 98SE SP2.1a with the memory tweaks.

I've been running a AMD Opteron 148 + ASUS A8V Deluxe + 1GB of memory and 98SE for quite some time with no problems, so I was surprised to have random blue screens on the other system so I'm trying to figure out if it's the motherboard, the CPU, or a software problem.

It might be your RAM. Try running MemTest86+ for a while.