Hi I just want to get a confrimation that the BSOD that i am getting is due to a faulty device driver. I've checked the ram with Mem test for 24 hours with no errors, did a dual instance of Prime 95 for 24 hours with no problems. Did a chkdsk no bad sectors nor problems. This happens when I play GuildWars in window mode and Mozilla Firefox is opened (at a flash heavy site). Here's a sample of my Debug.txt DEFAULT_BUCKET_ID: DRIVER_FAULT LAST_CONTROL_TRANSFER: from 8054a583 to 804f9c37 STACK_TEXT: b9c36850 8054a583 000000c2 00000007 00000cd4 nt!KeBugCheckEx+0x1b b9c368a0 bf802abb e2cfe150 00000000 b9c368c0 nt!ExFreePoolWithTag+0x2a3 b9c368b0 bf8a1e24 e2cfe150 e2d277a8 b605030e win32k!HeavyFreePool+0xbb b9c368c0 bf9d6808 e2cfe160 e3321a78 e2f4f018 win32k!EngFreeMem+0x1c WARNING: Stack unwind information not available. Following frames may be wrong. b9c368c8 e3321a78 e2f4f018 e1863010 bf9d5fd1 nv4_disp+0x3808 e2cfe160 00000000 001ff700 00000000 e2d277d0 0xe3321a78 FOLLOWUP_IP: nv4_disp+3808 bf9d6808 ?? ??? SYMBOL_STACK_INDEX: 4 FOLLOWUP_NAME: MachineOwner SYMBOL_NAME: nv4_disp+3808 MODULE_NAME: nv4_disp IMAGE_NAME: nv4_disp.dll DEBUG_FLR_IMAGE_TIMESTAMP: 4359a0b8 STACK_COMMAND: kb FAILURE_BUCKET_ID: 0xc2_7_NV___nv4_disp+3808 BUCKET_ID: 0xc2_7_NV___nv4_disp+3808 I'm guessing it's the Nvidia video card drivers, (Beta 81.17) but using the (81.15) causes them as well, I havent tried to use the 70's series yet. But i'm not sure wether it's the video card driver OR is it firefox that causes the problem. I've attached the full debug.txt and minidump. Thank you for your help in advance!