Random Automatic Reboots

My problem is random automatic reboots (0-3 times a day). System specs are in the signature at the bottom. This is a new system I built just a few months ago. I took several parts from another computer including the processor. That computer had a problem with random automatic reboots as well.

I have had the problem from day one on this computer. Automatic reboots can occur while doing most anything, even while I am away (computer idle). I know this because I have a boot-up password. I receive no error message or warnings prior to an automatic reboot. Sometimes I do get a black screen with a mouse cursor that won't move, sometimes a BSOD, then eventually it reboots. However, most times it just reboots with no warning.

Here's what I have done so far.

1. The first thing I thought of was the RAM. I ran Memtest and did find a few errors (1 or 2 per complete test suite). I checked each ram module independently. Both had errors. I replaced the RAM, rechecked with Memtest and still got errors. I changed out the RAM with 2 other brands, and still get Memtest errors. However, I ran Microsoft's Memory Tester and found no errors. So I am not sure if RAM is a problem or if the errors can be attributed to something else.

2. CPU temp is normal. I have never seen a CPU temp over 52C. It can handle up to 85C.

3. Originally, I was getting some errors in Event Viewer. Most of them were related to TCPIP. I have resolved those errors, but still get random reboots. After a random reboot, I check Event Viewer and there are no errors or warning messages.

4. I disabled "Automatic Restart" in the Startup and Recovery section of System Properties. I thought this would stop the reboot process and provide an error message, but it did not. I still get the random automatic reboots and no error messages.

5. I ran Chkdsk on the hard drive. No problems.

6. I have run all the regular mainteance we so often discuss.

7. I have run several registry cleanup and error programs including RegClean, EasyClean, etc. Still random reboots.

8. I have checked for viruses and spyware - no problems

9. I checked the mouse, keyboard, monitor and USB connections to see if a loose connection or plug problem could be causing the reboots. No problems found.

10. I checked the hard drive cable and even replaced it to rule this out.

11. I ran a full system diagnostic on my hard drive using the manufacturer diagnostic software. No problems.

12. I Checked the BIOS. Verified that Memory & Clocking are set to automatic detection. I am not overclocking.

13. I checked the power supply using a Power Supply tester. No problems.

14. I downloaded and installed the latest MB drivers.

15. I ran a couple different torchure tests. After only a few seconds at 100% CPU capacity, I get BSOD.

After all this, I am thinking the problem may be the processor or motherboard.

As I said, the processor came from another system which also had automatic rebooting problems. It's strange that both have the same problem and the common link between the two is the processor. I have an older processor that will work on this board. I may swap it out and see if automatic reboots go away. I am thinking this will confirm or eliminate the processor as the culprit.

The MB may also be the problem. It's a brand new board, however the onboard audio on this board has never worked. I had to add an audio card. I am wondering if the audio connections were bad, is there something else wrong with he MB that could be causing the reboots.

Although I think it is unlikely that the problem is the memory (because 4 different modules from 3 different manufacturers showed errors), I have noticed that the random reboots seem more prevalent when I am running 2 modules (1 Gig total) versus only one module.

Any thoughts or suggestions? Can anyone recommend other things to look at?

Thanks for your help.

Jim