For a while now, my system has been crashing while playing many different games. Sometimes they're the "illegal operation" variety, others they're fullblown BSODs. The two main ones have been "PAGED_FAULT_IN_NONE_PAGED_AREA" and "Nv4.disp", both problems which I've been informed can come from bad memory.
The crashes seemed to come about when I managed to kill the PC through overclocking (learnt my lesson there). I had the motherboard, graphics card and processor replaced, but not the memory, believing it to be ok.
I read up on Memtest and tried to use it under multicore mode, but it just completely freezes. Whenever I try it under singlecore, it reboots the computer when "Test" gets to 50%.
I apologise if I sound a bit clueless, I'm still learning the more technical side to PC maintenance. Any help would be brilliant.