Question Blackscreen with Z's on Startup

[Swaglit]

This issue started a while back. Sometimes when booting up, my PC would end up on one of two different blackscreens. Both with a flashing _ in the top right corner and one or two Z's in the middle of the screen. This would happen more and more frequently and by now I can't get it to boot up anymore.
I reset windows back when this started but it didn't help at all.
Before resulting in a blackscreen, it first shows the ASUS logo with a line at the bottom on how to enter the UEFI BIOS menu, which also doesn't work anymore

 

[Colif]

what asus motherboard do you have?

the flashing cursor means pc cannot find the boot drive and just stops, this can happen on motherboards that offer the motherboard a choice of boot methods and it chooses one that doesn't match the format the hdd is currently set to.

so before we change anything in the bios, need to see what hdd is formatted as now. Can you right click start
choose disk management and take a screenshot that shows all the drive details.

I assume you mean you can't get into the bios and not that the bios itself that doesn't work, as PC itself can't function without the bios.