intermittent freeze-ups

[zerocommazero]

I'm running out of ideas to troubleshoot my pc. It suffers from freeze-ups (monitor has frozen display and no reponse from keyboard, mouse). It happens at odds times. My box is dual-boot and it even froze up on the OS choice screen before boot-up once. It'll freeze up during activity or idle. Only way out is a hard restart.

First I replaced my power supply figuring it was getting flaky.
Then I switched hard drives and reloaded XP.
I've pulled out every PCI card in it one at a time.
Even swapped video cards.
I booted into and ran a memory tester with no negative results.

I don't know where to start to troubleshoot the processor, HD controllers, chipset, etc...

I've got a P4 1.8 Ghz with 256 Meg Rdram on a Intel Monterrey mobo.

Any ideas???? :confused:

[saphalline]

What two OSes are you dual-booting? And what other hardware do you have? What are your PCI cards? Does the freezing seem random or does it happen after a certain time period? Does it ever freeze while in the BIOS configuration? Have you checked for IRQ problems or other resources?

[zerocommazero]

right now i have no pci cards installed. only a video card in agp. i've swapped drives so right now there is no dual-boot. I've taken out or swapped all the variables except the mobo. This problem originally came out of the blue with no hardware or software changes for at least a month or so at all.