PC Freeze problem (lots of info)

Hey there. I've edited this opening post to a list in stead of a wall-of-text so it is easier for everyone to read.

The problem: Random freezes/reboots. More info here:

- The PC just freezes randomly in normal use, nothing triggers it, it can happen in 5mins or 50hours. The longest period it was without freezing was over a month. Definition of normal use: can happen in idle, can happen when playing, can happen when browsing the internet etc. you get the idea.

- The freeze is the basic deadlock, mouse, keyboard, everything stops functioning. Picture stays on, all the components and their cooling stay on, sound stays on sometimes. Solution = reset button.

- The freeze has happened in Windows (normal), the freeze has happened while loading windows, the freeze has happened in BIOS/POST, but HAS NOT happened in safemode, ever.

- Sometimes it doesn't freeze immediately, but the mouse starts stuttering when you try to move it (like lagging) for like 5 seconds and then the freeze happens.

- Sometimes the PC reboots itself after being frozen for like 10-30 seconds, no BSoD, just reboot. There are bugcheck errors saved in MEMORY.DMP when the PC has rebooted itself.

What I've already done while trying to solve the problem:
- Updated BIOS, OS and drivers.

- Run Memtest86 several times overnight (7-10 passes) with different slot combinations without any errors.

- Run Prime95 for 20hours to see if CPU or RAM overheats or gets errors, there were no problems.

- Tested PSU with a tool made for the purpose (PSU tester), it worked perfectly.

- Run Furmark for various amounts of time to see if the GPU overheats (or gets graphical errors) - there were no problems.

- Run CHKDSK several times to see if there are errors in my HDD, there were none.

- Observing temperatures in case of sudden changes and peaks - temperatures are always within safe numbers.

- I've also unplugged everything from the mobo, and plugged them back in case of a bad connection somewhere - didn't solve the problem.

- I've run virus scanner several times, there were never any infections. Using Avast by the way.

Known "issues", or if not issues, things to mention:
- I have RAMs with very, VERY large heat spreaders, thus I can't fit one of them to the first RAM slot of the motherboard, because CPU cooler is blocking it, I've only tested slots 2-4, first slot is always empty.

- The RAMs are running @1333MHz clocks, even though they are 1600MHz RAMs, but it is common with my CPU that the system underclocks the RAMs to 1333MHz, because it is the highest RAM clock my CPU supports by default, AMD Phenom II X4 965BE is the CPU in question.

- Few times when the PC rebooted itself during a freeze, the red DRAM LED has lit for 2-5 seconds.

- I don't know how silent new "modern day" HDDs should be, but my Samsung Spinpoint F3 is making weird sounds sometimes, and it's only 3 months old.

That's all I can come up with for now. Thanks in advance for any input.

Update your BIOS to 2005.

Sorry, mis-read your motherboard model. Try 1005.

Hi, sorry for responding so late, I had to leave for one week suddenly and now I'm back home. Before I got to update BIOS I got 2 freezes in normal use, these freezes were different in one way though; after being frozen for about 5-15sec the PC rebooted automatically and I noticed some deep red led light turning on for a sec or two inside the case, I'm pretty sure it is the dram led, I haven't noticed this before as I've had the case closed, but I had the side panel removed this time.

Also there's something I didn't mention before, that could be important from my observations; the RAMs I have are 1600MHz by default (I mean the recommended clock I think), but they are automatically downclocked to 1333MHz by my system, and from what I've read it's because the CPU I have doesn't support RAMs higher than 1333MHz, unless OC'd, so could the downclock that my system is doing to the RAMs be causing issues like this?

Anyways, I upgraded the BIOS like 30mins ago, now to wait and see if the freeze occurs again. Just thought I'd mention the stuff about the DRAM LED going on and about the ram clocks.

EDIT: Ok, BIOS upgrade didn't fix the problem, just got a freeze when I doubleclicked an application to start it up.

And the DRAM LED went on for a second or two again, even though I rebooted the computer manually this time.

You could have bad RAM... Try running Memtest 86 for several passes.

RAM - Test with Memtest86+

When you take that test run for at least 8 runs.
Then take a known good stick and test each slot.

Sorry, it's been a while and I forgot the specifics.

Can you check via speccy to what your clock settings are on the RAM?

Speccy - System Information - Free Download

I know mine on my ASUS motherboard were set wrong, they are 7-7-7-20 timing sticks, and my BIOS set them to 7-7-7-16.

Also, does it happen if you use onboard video instead of your graphics card?

This is what Speccy says about my RAM: 4.0GB Dual-Channel DDR3 @ 668MHz (9-9-9-24), also the voltage for each JEDEC is 1.50v.

This is whats written about the RAM timings of my model in the manufacturers manual: Each module kit has been tested to run at DDR3-1600MHz at a low latency timing of 8-8-8-24 at 1.65V. The SPDs are programmed to JEDEC standard latency DDR3-1333MHz timing of 9-9-9 at 1.5V.

And my motherboard does not have an onboard GPU to test with.

EDIT: Also, changed the first post from a wall-of-text to something more like a list for easier reading.