I have a 3 year old Windows 7 Pro PC that started ( about 5 days ago) shutting itself down. The PC shuts down as if I initiated shut down. All of a sudden it will say Windows is shutting down. If I have a bunch of programs open when PC decides to shut down, Windows will not shut down due to running programs. If I cancel the request to terminate the programs I have open, Windows does not shut down. This problem seems to happen every 1 - 2 hours.
Things I have done or can verify:
1) Inside of computer has been cleaned
2) Applied new thermal paste to processor
3) All fans are spinning
4) No malware on computer
5) Windows 7 Pro is activated. OEM license from HP
6) Tested power supply with Ultra Power Supply Tester - no issues detected
7) Currently running memtest - 3 passes, no errors
8) No bulging/leaking capacitors on mobo
9) Computer is offsite at a new location. So it's not the surge protector
10) Event ID 6008 and 1073 are logged around time of shutdown or attempted shutdown.
11) Power setting is set for high performance - no sleep
12) Ran SFC /scannow - no issues found
13) Verified hardware drivers are up to date
14) Ran speedfan. Temperatures are in range and normal
Hewlett-Packard HP Pro 3130 Microtower PC
Microsoft Windows 7 Professional Service Pack 1 64bit
Intel(R) Core(TM) i7 CPU 870 @ 2.93GHz (2.90GHz, 1024KB Level 2 cache)
4,096 MB RAM
SAMSUNG HD502HJ 465.76GB IDE
ATI Radeon HD 4550
I am at a loss and don't know how to proceed. Has anyone seen these symptoms?