Actually thats not a memory prob...Its a software conflict prob....you get that sometimes when you have Acrobat and MS Word and Norton AV on the same volume

It had been perfect for a few months until Wed., and I've had Acrobat, Word, and NAV on the same volume of every PC I've had since Windows 3.1. Never seen this before.

It seems to be having random software problems, which leads me to believe that it's memory or CPU, especially when it happens after the PC is on for 3 hours.

BTW, it's been 1 1/2 hrs since the last reboot after I took out one of the two 256MB memory modules.

True...the error message is more an exception and not the rule....Also from my programing experience "Instruction at (big long hex addr) referenced memory address (another big hex#) usually means error in code or irregular behavior in the program or a missing.
However you may be right it could be a sign of faulty ram..replace your memory and see if that fix your problem.especially when other programs also mysteriously crash. The problem you described happened to me just 3 weeks ago. When I replaced the ram, the computer worked just fine. Try downloading a ram tester from www.download.com to confirm your problem.

Now would be a perfect time to test out that MS Memory Diag. I'll give it a go and see what it says.* Also no re-boots in over 4 hrs.

P.S. The RAM definitely was the problem. The PC has been perfectly stable since I removed the offending memory stick. Luckily it was a Kingston with lifetime warranty, and it's replacement should be arriving today. Luv that Kingston! A few days before MSBLAST came out, I was having these problems, thought it was a virus! AAAAH!

Had same problem, replaced the ram-bingo.

I have a strange issue to discuss with you folks as well. I think it's kind of relevant to the topic.
My cousin fried his modem and bought a modem (Agere V.92 PCI)today. Installed drivers (from the CD-not digitally signed). Logged to net. After 5 minutes (or less), rebooted suddenly (BSOD-WinXP Pro). Changed the PCI slot and even installed the Win2K driver. Still the same. Tried out everything. Just opened the task manager to see if any process is causing this. It was MSBLAST. Ended that process. Worked fine.
I don't know whether MSBLAST was there on his system before he bought the modem, or it might even have installed with the drivers.

It just takes a few seconds just being online to get that MSBLAST worm. No user intervention required. It's a virus with an auto-infect feature built in! :angry:

glad you found your problem mikeh420.