Sometimes computer just freeze

[evilfox]

hello
my fathers pc has some strange issue, it frezes a lot! just cant move mouse and nothing moves!

i checked ram with memtest did 13pass with no error
did hdd check with hdtune pro returned no error on hdd only one reallocated sector in warning state
i had reinstaled fresh win7 x64 with latest drivers
with tempratures everything is ok, has a nice cooling system and system is @ wery normal temperatures
no minidumps as it doesnt go BSOD, reset only helps

pc spec
asus m4a78
cpu phenom2 x4 955 BE
ddr2 2x1gb + 2x2gb 800mhz = total 6gb @ 800mhz
asus gf8500gt 256mb
450w psu

what could i check to find out where is problem?

 

[Mark56]

Hi, first thing to consider is that Memtest can miss minor faults and as freezing is very often associated with your RAM I wold try running the PC on just one stick at a time, if the freezing persists then swap to another stick so you test them all. You may find it only freezes on just one of the sticks.

The other most likely cause is that the graphics card is either over heating or failing. Take the card out and run the monitor from the onboard graphics output and see if the symptoms persist. If they don't you can be sure the fault is related to the card.

Give the card a good clean with a can of compressed air. Clean the contacts with a soft pencil eraser and then push it in and out of the slot several times to clean the slot contacts. Blow out the slot with the compressed air and refit the card.

The final thing you can try is to go to the manufacturer's site for the card and download the most up to date drivers for your operating system and save it to your Desktop. Go into the Device Manager and find the card under Display Adaptors and then right click on the card description, select Uninstall and close the windows. Double click on the new driver and it will install.

If none of this has a good result then please post back and describe what happened.