Hi Techspot, My PC is freezing on a frequent basis. I've done what I can to diagnose the problem myself, but I feel I'm reaching the limites of my technical ability. If anyone has time to offer any insight, it would be greatly appreciated. I apologise in advance for the wall of text! The problem occurs in two ways: 1 - (90+% of the time) PC freezes instantly, no slowdown, no warning. Usually accompanied by a short, sharp burst of sound or static from the speakers. No bluescreen, no restart, it just stays frozen. 2 - (less than 10%) PC goes straight to bluescreen and creates a crash dump. These could both have seperate causes, I suppose I'm hoping they don't! There doesn't seem to be any regularity to these indicents - frequency varies drastically from every few days to every hour, and there's no pattern in terms of program useage - sometimes I'll be doing something graphic and cpu intensive, sometimes just browsing the internet or occasionally when the PC isn't even doing anything (in fact I just had one while typing this post!). The problem became noticeable after a system rebuild during which I replaced my Motherboard and PSU, as well as upgrading to Win 7. However, the system wasn't stable before this (it was worse) so it's possible that the problem existed before. What I've done so far: - I originally suspected faulty RAM, so I tried running on each stick individually. I experienced crahes with each stick (suggests it's not RAM, unless all 4 have gone or it's a compatibility issue). - I ran chkdsk, nothing unusual. - Researching the stop errors suggested a software or driver issue, so I ran a clean install, and installed the latest chipset and graphics drivers. Nothing for a couple of days (could point to something I installed after the first couple of days, could be a coincidence - that kind if spacing isn't unusual), but then resumed. - I tried swapping the graphics card since I had a spare to hand, no change. - Looking through Event Viewer didn't show much that seems suspicious to me. Lots of 41 Kernel-Power (which as I understand it just records that the system shut down unexpectedly) and 6008 EventLog (again, system shutdown unexpectedly). The one thing which may be significant (or may not) are a large number of 11 Disk errors with the description "The driver detected a controller error on \Device\Harddisk1\DR1." - these tie in to some of the crashes but not all. I don't know how significant this is, could the HDD be faulty? I guess the evidence points to a hardware fault, however my access to spares is limited and I don't really want to buy anything until I have a better idea what the problem is. I have an old PSU and RAM that I can swap in (I don't have them with me at the moment). I'd be suprised if it was the PSU or Motherboard since both are pretty much brand new, but stranger things have happened. HDD and CPU are both distinct possibilities since these are the oldest components in the system. Current system spec: Windows 7 64 bit Asus P5Q Deluxe mobo (Intel P45) Intel Q6600 cpu nVidia 8800 GTX 4x2GB OCZ Gold ram Corsair TX 650W psu Not sure about the HDD spec Error Messages (I've only had 2 that produced crash dumps since the reinstall) ============================================== Problem signature: Problem Event Name: BlueScreen OS Version: 6.1.7600.2.0.0.768.3 Locale ID: 2057 Additional information about the problem: BCCode: 1a BCP1: 0000000000041287 BCP2: 0000000000000030 BCP3: 0000000000000000 BCP4: 0000000000000000 OS Version: 6_1_7600 Service Pack: 0_0 Product: 768_1 Files that help describe the problem: C:\Windows\Minidump\033010-18720-01.dmp ============================================== Problem signature: Problem Event Name: BlueScreen OS Version: 6.1.7600.2.0.0.768.3 Locale ID: 2057 Additional information about the problem: BCCode: a BCP1: 0000000000000048 BCP2: 0000000000000002 BCP3: 0000000000000000 BCP4: FFFFF80002ACE8A2 OS Version: 6_1_7600 Service Pack: 0_0 Product: 768_1 Files that help describe the problem: C:\Windows\Minidump\033110-18283-01.dmp ============================================== See attached for minidumps. I have the error messages from before the reinstall, BCCodes were a variety, including d1, 4e, 1000007e, 50, a. Unfortunately I didn't copy the minidumps when I reinstalled, so I don't have those.