Goodevening all (at least it's evening here ;-)) Recently a friend of mine aqcuired a new computer, that is to say we went out and bought all the parts and put the computer together ourselves. From the start he had BSOD's. As I am aware the cause can usually be found in faulty hardware. My friend being the amateur at this I went over and did a memtest. First on both sticks together, then seperately. It turned out one of the sticks was faulty. As these were under warranty he proceeded to use the non-faulty stick until he got both replaced. When we however got the replacement set and installed it the system wouldn't even load into Windows, instead just gave us a BSOD. All we got to see was the Windows 7 loading screen and then everything went blue on us. The system ran fine (that is actually booted up and could be used) using only stick (although it did BSOD once too, running one stick). It also booted up when we put both sticks in slot 1 & 2 (in other words, not using dual channel), but he still got BSOD's every so often. He's been having a few BSOD's the last couple of days ever since getting new RAM. I assumed one or both sticks were faulty again but here is the weird part: we ran memtest twice and it didn't give any errors. Today we ran memtest again and it gave a tens of thousands of errors. We then proceeded to test the sticks seperately, to figure out which one was faulty, only to see both sticks complete a memtest without any errors being present! I'm not sure what to think now. Could the RAMbanks on the motherboard be faulty? I've gone ahead and put the sticks in slots 3 & 4 which actually had the system boot up properly, we're still waiting to see if it will BSOD now too. Meanwhile I have tried uninstalling his virusscanner as well to see if that was the problem, but the BSOD's were still there. These are some of the stop messages: - Page fault in non paged area (multiple times) - Win32k.sys (once) - Bad pool header (once) - System service exception (multiple times) Sometimes he'll get the BSOD at first start-up after cold-boot, sometimes when he plays a game. To sum it up, these are the things we've tried and done: - Memtest, came out fine four times, gave errors once but not after that anymore - Uninstalled virusscanner - Did a chkdsk, came back completely fine - Tried sticking the ram in different slots as well as using only one stick I've also gone ahead and took some of the minidumps that were on his computer, perhaps that could be of some help trying to figure out what the problem is. I just don't know anymore. Any help would be appreciated!