Computer choosing to shut down

Windows 7 computer - running happily since W& introduced.

Over the last couple of days I have returned to it after being away from it for an hour or so to find that it appears to have shut down. The blue light on the case is off - like it is when shut down - but the fans are still running. The screen appears to be in standby (blank with orange instead of green light) but will not of course show anything - if you turn it off and on again it goes immediately into standby again)

If I reboot I get the usual Windows did not shut down correctly message, to allow me to choose safe mode or whatever - but then boots up normally if I wait. Any ideas please. As you can guess - I am not technical!

I don't know if this is a hardware or software problem.

 

OK -done that - I 'll see what happens.

Thanks

 

Eek!

Not the answer I wanted - but the one I feared.

Thanks anyway - more investigations to do

 

Just a thought - could a physical memory fault also account for the computer having problems while when trying to run a plug-in in Photoshop and it crashes due to a lack of memory availability and also is unable to export the clipboard when closing Photoshop down due to inadequate memory?

The plug in runs normally the first few times before exhibiting this problem. It always used to work OK on the computer before it was upgraded (fresh installation) to W7 by the way.

 

Before you start to worry about heat go to your control panel and click "system and security" when that opens go down the list to "power options" and click , on the left panel you will see "change when computor sleeps" open that and check the settings.