Windows failed to boot, mouse doesn't work, USB keyboard doesn't work, PS/2 keyboard doesn't work. What do I do?

I still am unable to solve this damning issue on my PC. I tried to use MSI's BIOS updater program, and upon restarting it bricked my PC. I'm stuck at the Windows Boot Manager, and i do not have any control at all. The mouse and keyboard don't work, and i even tried buying a PS/2 keyboard as an alternative control method and it doesn't work.

What am I supposed to do? I need this PC for school and work

EDIT: Switching the motherboard from BIOS-A to B let the keyboard work. Turns out MSI's update tool has a high chance to fail. Makes you wonder why they even allow it.