If you can get the cursor to work at all take a look at your power management settings.
Also look in device manager at the keyboard and mouse settings.
If you can't get it to work at all try booting to safe mode.
Try an external mouse.
On my fiance's Dell Laptop computer, the cursor moves but will not activate anything, the computer is running Windows 10 and had been operating fine until this glitch. The only way to shut down the machine once it is activated is to hold the power button down, you can move the cursor to the bottom left corner all that you want and the window will not activate.
My fiance just told me that when the screen goes black from inactivity neither moving the cursor nor striking any keys will wake it up.