Yesterday for no apparent reason my computer suddenly restarted, it has continued to do this at regular intervals since. 
Things I have done so far.
I have turned off the restart in windows but it continues to restart without giving me an error message.
I have tried another hard drive to rule out both a driver and windows problem, but without success.
I have unplugged all usb devices and also changed both mouse and keyboard.
I have stripped it bare and reseatted the heatsink, cleaning the fan from dust.
So does anyone have any clue or has anyone experienced this and can point me in the right direction?
I was thinking it must be a heat issue but monitoring my temps and they remain about 29 for case and 32 for cpu.
This leads me to believe it is a hardware fault and it can only be one of...
Memory, motherboard, Graphics card, cpu or power supply.
Which is most likely to be the cause or is there anything else you could suggest.
Many thanks.
Things I have done so far.
I have turned off the restart in windows but it continues to restart without giving me an error message.
I have tried another hard drive to rule out both a driver and windows problem, but without success.
I have unplugged all usb devices and also changed both mouse and keyboard.
I have stripped it bare and reseatted the heatsink, cleaning the fan from dust.
So does anyone have any clue or has anyone experienced this and can point me in the right direction?
I was thinking it must be a heat issue but monitoring my temps and they remain about 29 for case and 32 for cpu.
This leads me to believe it is a hardware fault and it can only be one of...
Memory, motherboard, Graphics card, cpu or power supply.
Which is most likely to be the cause or is there anything else you could suggest.
Many thanks.