Can't access bios after legacy boot

What happened is this: Basically, I was running Windows 10 on Acer Predator G9-791 and I sort of played around in BIOS.

When I have changed the boot mode from UEFI to Legacy and restarted the laptop, I could only see a somewhat smaller logo on boot that says "(Acer Predator image) Predator", but nothing happens after that.

That would not be a problem if I could just switch the boot mode back to UEFI, the problem is, that after this change to Legacy I can no longer access BIOS with F2, I tried using different keys (del, esc, f1-12) but that didn't work either, please help, what should I do?

EDIT: When I removed SSD with windows, it booted to some sort of terminal or something and it keeps saying:

Intel UNDI, PXE-2.0 (build 083) Copyright (C) 1997-2000 Intel Corporation.

For Qualcomm Athernos PCIE Ethernet Controller v2.1.1.5(03/15/13).

Check the connection! PXE-M0F: Exiting PXE ROM. No bootable

device -- insert boot disk and press any key

TL;DR: I can't access BIOS anymore after setting my boot system to legacy

This is how I have managed to solve this:

• Remove the SSD/HDD that contains Windows10 boot (or any other boot drive)
• Start the PC and instantly spam F2 key (or whatever is the key to access your BIOS)
• You should now be able to see BIOS.
• In BIOS, Change the boot system back to UEFI (in case the option is no longer there, restore the factory settings of BIOS)
• Shut down PC
• Connect the boot drive
• The PC should now be booted into Windows (or any other OS)

Although, I still do not really know, why I wasn't able to access the BIOS instantly without removing the SSD, but this solution has worked for me