Blank screen on changing boot settings

[ncubedaisy]

My Acer P253 was showing an error message saying that there was no boot system. I pressed f2 and del and changed to uefi. Now its showing a blank screen with hyphen on top left of screen. I have tried pressing f2, f9 f10 and del but to no avail. What should I do?

 

[Lutfij]

Which BIOS version are you on? See if going into Legacy mode retrieves the list of boot devices for you.