just re-booted my pc got error pfn list corrupt am i right in thinking this is ram or hard drive related i did run memtest for 16 hours then stopped it thought it was playing up thats why it was running so long or does it run that long i have 2 gig of ram vista intel quad core 6600 2.40 ghz. 64 bit operating system memtest did show some error but how reliable is it.