Ultimate Boot CD

OK, I have two computers. This one runs WindowXPsp2 and is running well. The UBCD also works in this machine. That's the base line.

The other machine is having problems: Illegal instructions, GPFs, that kind of thing. I tried to do a repair install of Windows98se, then a clean install. Neither would run through. After the first re-boot, the install would error out and quit.

I got the UBCD to try to figgure out what was going on here. UBCD will boot and some of the programs will run. Memtest86 and memtest86+ run several passes without errors. But other tests will hang or error out when loading Himemm, emm386, or Ramdrive. This makes me think I have a memory problem above 64K. But why couldn't it be detected??

So:
What's the best test to shake up the memory on this machine?
Or what other areas should I be looking at for problems?
Some of the tests (I forget which) say unsupported Chipset. This is an OEM computer that was built by a local shop. It has a PC266(??) PCCHIPS Motherboard. (hmm, maybe I see the problem here)

Try running the memtest over night, sometimes it will be fine for a few iterations and then start to have problems.. I usually will run Memtest86 and/or Memtest86+ for at least 12+ hours before I consider the memory relatively error free..

One thing to try also is to disconnect all components that are not needed - ie. sound card, modem, NIC etc. this will help to rule out those as problems..

Also, what kind of errors are you getting? PCChips aren't the best motherboards in my experience either.. If you can find an updated BIOS (good luck) - try flashing it..