Answer:
This document contains recommendations on what to do if the computer frequently freezes or completely halts. An easy way to determine if your computer is in this situation is by pressing the Num Lock button on the keyboard and watching the Num Lock led (light) to see if it turns off and/or on.

If you're able to get the light to turn off and on and are running Microsoft Windows, press CTRL + ALT + DEL and attempt to end task the program.

Make sure the computer is really frozen
Although the above Num Lock trick is a good indication on whether or not the computer is really frozen, it's still always a good recommendation to give the computer at least a minute before turning it off.

Reboot the computer
After waiting a minute, reboot the computer; it's completely locked and will not recover. Keep in mind that all work being worked on is going to be lost and cannot be recovered if the information has not been saved or automatically saved.