HI, I am Dave, I will help you with this.
It is safe to stop that process in Stage 4 or 5, that will not affect your files.
Press and hold the power button on the case of your PC for 5 - 10 seconds to perform a hard shut down.
Wait a few seconds, then start your PC again
If the disk checking starts again, press any key on your keyboard to cancel it
Does your PC then go into Windows' normally?