Hi, I am Dave, I will help you with this.
1
Does this method get you into the Recovery Environment?
Start your PC, just as Windows attempts to load (spinning dots), press and hold Power Button for 5 - 10 seconds to perform a Hard Shut Down
Do this twice
On the third start Windows will boot into the Recovery Environment and from there you can access System Repair, Safe Mode, Command Prompt... etc.
2
If not, can you get into Dell OS Recovery using this method:
Force your PC to shut down by pressing and holding the power button on the case of your PC.
Start your PC and as soon as you see the Dell logo screen, repeatedly press the F12 key and from the resulting menu, you should be able to access the OS Recovery option.