Hi Guys New to this forum but fairly experienced with PC. Currently pulling out my hair with this one ... apologies for the lengthy post. . . I will attach SF Diags and CPU-Z snips. . . System is randomly crashing but no dumps.Crashes are NOT BSOD. (but see further down). There are two versions of the crash - first is a spontaneous re-start, like the reset button has been pressed. The second is the screen get completely corrupted and the PC locks-up, have to power off/on. In both cases there is NO DUMP file produced. Event viewer has the default (useless) "41 Kernel-Power" entry. This is driving me NUTS! It has been going on for weeks now. I have replaced the PSU with brand new 530W. Swapped RAM (DDR3) with another machine. Run DiskChecking on all drives (HD Tune) - No Errors. Taken out the graphics card and used onboard graphics. Done a complete clean out of system - clean re-install windows 7 Pro SP1. Updated BIOS. Updated all drivers. Device Manager is clear of all issues. Crashes still happening - randomly. Can be 3 in an hour or up to two days in between. Happen when I am stressing it or when it is idle. I noticed that in the event viewer most of the crashes I have been having coincide with an error in the event log - "Session "Microsoft Security Client OOBE" stopped due to the following error: 0xC000000D". Followed instructions form other forums - like uninstalling MS Security Essentials - but no change. Today I even swapped out the motherboard for an identical one from ebay. Got it all installed and working - and it is STILL crashing. HOWEVER - I did get 2 BSoDs (about 10 mins apart) - and two dumps. Bug Check points to "Memory_Managent". (also event viewer showed "Session "Microsoft Security Client OOBE" stopped due to the following error: 0xC000000D" again). I am completely at a loss now . ALL of my hair has been pulled out and ANY help from you experts would be much appreciated. . .