CPU: Core i7 4770K Haswell (Socket H3 (LGA1150) Motherboard: ASUS Z87-K Ram: PC3-10600 (667Mhz) 8GB x 2 Sticks GPU: Intel HD Graphics 4600 HDD: Seagate 500GB Solid State Hybrid Drive (SSHD) + 1TB Standard HDD PSU Corsair Builder Series CXM 500W Modular 80 PLUS Bronze Certified ATX/EPS PSU OS: Windows 7 Professional 64-Bit SP1 Bios Version 0309 (04/07/2013) Crash Details: System randomly reboots, no warning, no specific applications running at the time, can happen 5 minutes after boot, or it can happen 6 hours after boot. Important Information: The customer is a professional DJ that does events around the country, and uses software called "Cubase" and "Reason" with lots of plugins (100+) that need to be installed and tested each time a re-install is done. History: This is a brand new system build, Initially I installed Windows 8 Pro 64-Bit which was working flawlessly for two weeks, after installing all needed software etc. After the customer tested it he realised that his £500 MIDI keyboard used to make songs didnt work because there was no driver for windows 8, and also his camera's that they used to stream video directly online for the radio station they work for, doesn't have window 8 drivers. I explained that window 7 64-bit drivers may work but ultimately he had decided that he doesnt like/want windows 8. So I re-install windows 7 64-Bit, all working fine, install umtine plug-ins and software AGAIN! and test for a few days, no problems. Deliver it to the customer, he tries it out, and then 3 hours later calls me and says the PC has rebooted 3 times without warning..... So I logged on remotely and immediately checked the event log, and under administrative log I could see several dirty shutdown events, often followed by errors of services not starting up, after goggling many of the errors, they were mostly "ignore this as this is a file left behind from the OS installation media" Differences from Windows 8 Install - Windows 7 Install: *Windows 8 found it's own drivers automatically and because windows 7 couldnt find drivers I installed via the motherboard disc, this in turn installed ASUS Suite III which I have subsequently un-installed. So here's what I have done so far: *Updated all drivers *Removed any additional PCI cards and only left the bare essentials *Tested the PC at my workshop to verify it was not the electrical source (extension lead running 10+ items) = still reboots when directly into the mains source *Performed a system restore to the day I gave the customer the PC, before he installed his DJ hardware, this results in less reboots, but still had two today. *Checked Speedfan which shows temps at 25-30c, but cannot detect volts on PSU. *Only one BSOD minidump has been created and points to netbt.sys on the 16/08/2013, so I updated the network drivers, since then frequent reboots and no further minidumps. Event Log: I have checked all the errors I can see, but I will upload the saved event log just incase somebody with more knowledge than me can analyse it further.