John Jones wrote:

Samsung - Bought 2011 [no mention of model or type of computer]
Windows 7 Home Premium 64-bit

When I left on holiday 2 weeks ago my laptop worked perfectly.
When I booted today it got as far as the desktop screen and then silence
fell. I rebooted and everything seemed ok again. Until returning after lunch
it woke up, thought about life, went unresponsive, and then gave me the
black screen of death.

I am obviously somewhat perturbed, although by posting this clearly it
is ok at present.

What does "woke up" mean? That you saw your desktop and then there was
a delay before the screen went black?

Did you yet try booting Windows into its safe mode and letting it sit
idle for awhile to check its behavior without all those startup programs
running?

Have you tried changing from whatever power option plan you are using
now to using the high-performance power plan (which does NOT put your
computer into standby or hibernate mode)?

Did you try disabling your screen saver?

Have you tried disconnecting all peripherals (except keyboard and
mouse), booting, and letting your computer sit idle for awhile to check
its behavior upon returning to use?