Reboot your PC.
Long story short, something went critically wrong with your computer.
See if this happens again.
If it does, you need to rule out whether is is a software or hardware issue.
Most modern PC's have onboard diagnostics.
Reboot your PC and hit the "F12" button every 3 seconds. That should take you to a black/white screen with choices. If you see the windows splash screen, you've gone too far.
From there, you should have the option to run hardware diagnostics.
If it's software, reinstalling the OS is the easiest way to fix these types of issues.