Unable to see screen

[Septide]

Okay so I had my SSD installed by my stepdad and I was in the bios options, (he had it set to prioritise ssd) and accidentally set it to prioritise my hard drive first and now when I try to turn on my computer it's like it doesn't register my screen. The computer itself still had everything working and on its just like there is no screen plugged in. Anyway I can fix it?

 

[Multipack]

System spec?

You need to either to unattach the HDD , get into your BIOS quickly or reset CMOS basically.