Well, I think I may have solved it. The wife forced me into it. She said I couldn't play with, not even take it out of the box, the new computer (got it in May) untill I put the other 2 back together.
To recap, so you don't have to go back to the begining. Xp runs fine on this computer, except it took a dislike to pogo. It would just shut down and restart. 98se, no problem.
So, since I'm not working right now, I figured it would be a good time to see what I could do.
Problem computer finally threw a BSOD error
0x0000009c (0x00000001) (0x8054d5s0) (0xb2000000) (0x00000115)
and I had to do it again to see if it would give the same error
0x0000009c (0x00000001) (0xf2000100) (0x00000800) (0x00000800)
not quite the same but same type. These point at ram or hardware, so you'd think it would happen regardless of OS.
Google wasn't much help, lot's of similar problems, game playing related, but no solution.
Memtest would stall at the same point with a Unexpected Intercept_Halting error. Same code each time. Both pieces of ram or just single piece.
Ran memtest on the ram in the Compaq (yes, it's going again, just needs it's hard drive). It was ok. So I put the ram from the problem computer into the compax, it was ok. At the same time I put the 133mhz 256 (compaq's other one is 100) from the compaq into the one with the problem, it stopped at the same point in memtest.
Again, no solution on the net for the code.
A check with Intel's processor Id tool tells me this CPU is overclocked by 33%.
So the logical thing would be to back it off a bit.
But knowing the computer ran xp on pogo with no problems before, instead I looked for something else.
My theory was xp made the cpu work harder than 98se. I was close. To carry on, it seems xp can listen to and act upon "commands" from the cpu, were as 98se can't. That explains the shutdowns with one OS and not the other.
Solution, cleaned the cpu heatsink. Ran memtest, this time it made it to the end. Immediatley pogoed for half an hour while things were still "hot". It seemed fine.
To tie it all together, it seems the cpu was complaining about a heat problem that both xp and memtest would respond to but not 98se.
I tried Fanspeed, but it would only report the HD temp, but for others, with a newer system this program should help.
So if anyone has a similar problem, especially game playing this may help.
The wife can drive it around for awhile and we'll see.
edit ti add: btw, I left it overclocked.