Hello all. I have the following pc specs and would like to know if there is a possible solution to my problem: System Manufacturer:ECS BIOS: Default System BIOS DirectX Version:10 Operating System:64Bit Vista Ultimate Motherboard:Elitegroup P4M900T-M2 Supports DDR2 667 up to 4GB Power Supply Unit:450Watt Hard Drive:Seagate 160GB SATA RAM:2046MB (2x1GB DDR2 667) Graphics Card:Zotac NVidia GeForce 8600GT; 512MB dedicated video RAM(total approximate memory:1264MB); Pci Express; DAC type: Intergrated RAM DAC(not that I know what DAC type is) Sound:On board Display: Dell 21.1" wide LCD The problem that I have is the fact that I get random blue screens. The stop messages are listed below. This happens very often and I even tried formatting and while I'm in the process of installing Windows then I get a blue screen with either one of these messages. There is no particular order in which it happens so I cannot predict when it happens and therefore can't do troubleshooting or process of elimination on my own. Even installing XP makes no difference. I've tried removing the graphics card completely and uninstalling all the software and drivers for the card and running from onboard VGA as I initially thought that this could be a problem relating to the graphics and as I've said, process of elimination does not work/help. Some one on the forum suggested to some one else with a similar problem to simply change the fast boot setting (in CMOS/BIOS setup) to normal boot and this also doesn't help. I've done memory diagnostics test and even then do I get a blue screen. I have, however, managed to complete the memory test with 3 passes and this says that there are no problems. I assume that the problem is then therefore not a sustainig or constant one for the tests to detect it but rather one that just happens at a certain point/time. A friend told me that I might need a higher powered power supply, but for crying out loud, I have a 450W unit which should suffice and it came with the system. I also checked that all my fans (CPU, PSU, and Graphics Card fans) are working properly and they are. At least they seem to be. So that should rule out overheating. What to do, what to do. These blue screens seem really dangerous and I am a little concerned that if I continue to use my machine then it will break for good. Is this the case? Another question that I have is do you think my motherboard can support DDR2 800 RAM and could it be that I need this particular RAM? Although I, myself, doubt this. PAGE_FAULT_IN_NONPAGED_AREA STOP:0X00000050(0XFFFFF6800685FA58,0X0000000000000000,0XFFFFF8000988A317,0X0000000000000002) PFN_LIST_CORRUPT MEMORY_MANAGEMENT STOP:0X0000007E(0XC0000005,0XF748E0BF,0XF78DA208,0XF78D9F08) pci.sys-Address F748E0BF base at F7487000,Datestamp 3b7d855c IRQL_NOT_LESS_OR_EQUAL STOP:0X0000000A(OCOOOD864,0X00000002,0X00000000,0X804E8AC5) Beginning dump of physical memory Dumping physical memory to disk PAGE_FAULT_IN_NONPAGED_AREA STOP:0X00000050(0XFA75C4DE,0X00000000,0XF7B76E16,0X00000000) Ntfs.sys-Address F7B76E16 base at F7B52000,Datestamp 47500575 Beginning dump of physical memory Dumping physical memory to disk I really do appreciate all the help and thanks alot.