Can't switch to external monitor after factory reset

[Billion456]

So I have a broken laptop screen and I had it hooked up to my monitor but the laptop was really slow so I wiped it but kept windows (stupid I know) but now I can't get it to switch back to the monitor. I'm guessing I have to go through all the fresh start up stuff but I can't do it with a blank screen. Laptop is a hp pavilion 15

 

[The Paladin]

have you tried to press the FN + screen switcher key?

 

[Billion456]

Yeah ive tried that and I've tried disconnecting he screen so it uses the monitor as default but still nothing