Hi Em )(,
I am Dave, I will help you with this.
A Windows update can take up to an hour if it is a major feature update.
Please give that more time, if it is still stuck on 'Getting windows ready' after another 30 minutes, you have no other choice, 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 secodns and start your PC, does it boot into Windows normally?