I/O operation initiated by the Registry failed unrecoverably

This morning my laptop has started to suddenly power off after running for just a few minutes. After restarting, the problem persists. The event log indicates the following critical error:

Code:

An I/O operation initiated by the Registry failed unrecoverably.The Registry could not flush hive (file): ''.

I have tried the following trouble-shooting steps thus far:
- chkdsk which found no errors.
- CCleaner to check for registry errors
- Malware check via Malwarebytes in Safe-mode
- Virus scan via Microsoft Security Essentials

Is anyone familiar with this error and could let me know what my next troubleshooting steps should be? Thanks.


System: Windows 7 x64
Hardware: HP g6-1d60US
2.5GHz/1.9GHz VISION A4 Technology from AMD with AMD Dual-Core A4-3305M Accelerated Processor
4GB DDR3 SDRAM (1 DIMM)
AMD Radeon HD 6480G Discrete-Class Graphics

Have you tried a system restore to a restore point before the problem occurred?

Thanks for your reply. I opted to do a reformat and clean install. After the reformat the problem persisted so I ran a memory check. The check was interrupted by an unscheduled power down. Upon reboot I got an overheating issue. I installed CoreTemp and the CPU temp was in excess of 90 degrees C. So, I think the problem is likely a broken fan. I've ordered another one, will replace thermal paste during install and will post back if those steps don't eliminate the problem.