My computer sometimes doesn't respond after leaving it alone for a while

[UltraFireFX]

Sometimes, when I come back to my Windows 8.1 Desktop, all I get is a black screen no matter how many times I press buttons on my keyboard or mouse, restarting my monitor doesn't help either.
I need to hold down the power button and do a full restart to use my computer again,
any ideas?

 

[YourLocal]

It might be your hardware.

 

[UltraFireFX]

It might be your hardware.

Or, it could be paranormal activity.
Please explain or justify your comments, otherwise they are a waste of time for everyone.

 

[YourLocal]

It might be your hardware.

Or, it could be paranormal activity.
Please explain or justify your comments, otherwise they are a waste of time for everyone.

They're actually just wasting your time. Maybe your C Drive is dying or dead.

 

[UltraFireFX]

I found a similar thread here if anyone wants to look. http://www.tomshardware.com/answers/id-1748599/black-screen-computer-running-locked.html