hello mate,
best program i have found by far is intel burn in test ...i've used memtest loads of times and got passes then system still random blue screens .. then i found out about Intel burn in test which is supposed to be the test intel uses, dont quote me on that though lol ... anyway that tests ram and cpu always finds fault where memtest passes , test ram 1 stick at a time using intel burn in and set the sofware to us max ram .. even if ram timming are correct this software will find any probs if there are any with cpu or ram