Your temps are more than fine. I believe the CPU shut-off temp is 100C, 212 F, so you have plenty of room on that front. Re-seat all the cards in the slots, keyboard, mouse connectors too. Also check if you have any capacitor that are popped or looking bloated. If that doesn't work, reinstall the video drivers. If you still have problem, test with only 1 video card at a time. Test your RAM too. That's all I can think of at the moment.
Try uninstalling your video drivers and install the latest release from nvidia. I had a similar problem. Its gone now. I think its the generic win7 64bit drivers.
------------------------------------------------ ------------------------------------------------------------------- ---------------------------------------------------------------------- I did try a few times to install the latest nvidia drivers and since installing w7 64 the drivers fail to install. During installation all of the monitors start to flash intermittently and there is no return to a normal mode. I have to cancel install each time. The computer does not freeze up at all when this happens, the video drivers just fail to install. I will take good advice and re-seat everything. Will also check the ram .I will try any and all help I receive. The motherboard battery I was not aware of. Is this something that can be tested to check for weakness ?
Take out your 8400 and then Install the latest driver. After you can pug it back in. When the computer freezez are you able to Do CNTRL + ALT + DEL ? and access task manager. Only hit the combination once.
I am going to take apart this evening and give it another cleaning also re_seat everything. I wil then take out the 8400 and follow your suggestion to install drivers. When computer freezes I cannot use the keyboard. None of the keys work including the mouse no longer works.
You might try reseating the processors. I wonder if lockups happen if the computer is in safe mode (safe mode uses fewer drivers.)
I have been my own computer repairman for a long time and I happen to have a similar problem a few years back...the culprit, a bad stick of memory. Order a new set from newegg or tiger and replace it. If the problem persist return the memory (usually they take it back free of charge) and it wont cost you anything to try this remedy. My guess is you wont have to return it. Don't replace just one stick, replace the lot of it and my guess is you'll have smooth sailing.
Running Memtest now for the ram. I need to pick up a dvd for the memtest86, so for now running this version. This looks like it is going to take some hours to complete so doubtful I will be able to get to the computer to take apart this evening. I am running 3 instances of memtest at 2047 mb per instance. The computer has 8 gb of ram installed. Is this the correct way to run memtest, or should I run 4 instances ( quad core cpu ) at 2047 mb ? attached is what test looks like so far. After I take everything apart inside computer and put it back together I will run memtest86.
Yep I had the same prob and it turned out memory was the prob. Memtest did not find the problem. I would just run each stick one at a time till it because obvious that one stick was the prob. You rules out heat, and reinstalled the os. So memory would be my next go. Next would be an HD conncection prob. Then checking each graphics card.
MemTest still running about 70% complete and nothing has surfaced yet. After this test completes and everything has been cleaned, re-seated I will run one stick at a time and see if anything can be found followed up with video cards/ drivers.