The IRQ_NOT_LESS_EQUAL error is normally graphics card drivers related, start by installing the most up to date drivers, and if you still get the same problem then try the driver disk that came with the card and wait until the current latest drivers are updated before trying them again!
Also, check the timings on the RAM are set correctly, I have 1333MHz Corsair XMS3 in my big i7 box and that defaults to the wrong timings so I have to set them manually to get a nice stable configuration, I think from memory they were 9-9-9-24-2T |