Hi everyone. I upgraded my system's ram a couple of days ago and ever since then, my computer has been restarting randomly every ten or twenty minutes. System Specs: 2.8ghz Intel P4 Windows XP Pro ATi Radeon 9800 Pro Maxtor Sata 150 300gb HD 500 watt PSU 2x512mb Kybte Ram 2x512mb OCZ Ram (upgrade) My motherboard has 6 slots total (for dual channel ram). 3 slots in each pair. After researching the problem a bit myself, I'm think there is something up with the new RAM I've installed. I gone ahead and disabled something under System Properties in Windows that prevents the computer from restarting whenever there is a fatal error. Instead I'm taken to window's blue screen of death and receive the error: "DRIVER_IRQL_NOT_LESS_OR_EQUAL" I took the liberty to go ahead and run Microsoft's Windows Memory Diagnostic Tool (I created a bootable diskette). When I first ran the test, that is with all four sticks seated on my motherboard, test 4 and test 5 failed every pass, LRAND and Stride6 respectively. I then tested each RAM module individually and much to my surprise, each individual RAM module succeeded on every test on multiple passes. I tested each individual slot on my motherboard by running the same test with a known working RAM module individually on each slot. Again, everything worked out fine. I tested my dual channel K-byte RAM by itself on slots 1 and slots 4 (first slot of each pair). No problems here. I did the same thing with my OCZ dual channel RAM and again no problems. When I combine both kits, as in when I have all 4 modules running togethers, thats when my RAM ends up failing the memory tests. I'm finding all this quite strange. Any idea on what could be happening?