Try this first, then try the hard shutdown, then if necessary, I'll find instructions for using the Recovery drive.
I'm reading the tutorials re: Recovery / Recovery drive, but I seem to be in a loop. Still looking and reading.
Download and unzip DriveCleanup
This utility removes USB devices that are no longer connected to the system
Boot to 8.1 and disconnect the mouse and KB, the transceiver if wireless (USB - yes?)
Connect the mouse and keyboard to different USB port(s).
If you have control over 8.1 run driveCleanup
then run the malware scanners I posted earlier.
If you cannot use your mouse or KB, try this next:
shut down your machine hard 3 times in a row.
hard shut down: boot into Windows then press the power button to turn off the machine.
The 3rd (4th?) boot should automatically boot into Recovery.
select Startup Settings (you might have to select Advanced options, then select Startup Settings)
select Enable Safe Mode
-> with Networking
sign in with an account with administrator privileges
see if any of that helps
When you say ... so I can try to do a system restore to a state previous to the problem. what do you mean?
Do you have a System image that you previously created or are you referring to a System Protection Restore Point?
I think you can do either in Safe mode, but I'm not certain.
You will be able to run drivecleanup and the scanners in safe mode, assuming the mouse and KB are working.