system unstable

[regan1985]

i seems to be having trouble with my pc after months of working fine, it started to restart when watching a movie so i thougt i bet its a windows problem so formated a couple of months ago, 2weeks later it started again so i purchased a new psu coz my old one was kinda old. it still happened so i took a stick of ram out and still happened and then tried the other stick and it was still unstable so the last thing i could try is my graphics card tried an old one and still no good. funny thing is when i test in with orthos for 12hours it runs fine but if i try windows memory digonostics it stops running and crashes sometimes. because it doesnt seem to crash all the time just randomly my thinking is that its the motherboard? i am borrowing my friends ram next week to see if it makes any difference but before then has anyone god any ideas?sorry i seem to go on a bit

[jagd]

If it is crashing at memory test probably ram(s) is/are problem .Can you test with memtest ?

http://www.memtest.org/

[regan1985]

i have tried mem test and i did 300 passes with no errors, i also did a windows 7 memory 7 it passes the basic test and medium test but when i do the advanced test it gets stuck on 10% i tried every slow and both ram sticks and still did the same, everything in bios is set to default and i have raised both the north and south bridge and fsb voltage and cpu voltage and still stops at 10%. also i have run orthos and it passes after 8 hours of testing!

could it be my psu or would doing those tests ,test the psu?also it could be my video card but i have tried far mark and other then it getting very hot 90c it doesnt crash!