When loading the computer, you will need to press the keyboard key combo to access the BIOS. This can be any number of combinations or a single key, depending on your computer maker.
But it's usually the DEL key.
Then go through the options til you find where it gives you the option to load keyboard from USB.
Hopefully you still have an older PS/2 or DIN keyboard you can use to access the BIOS in the first place.