How to format a USB memory key If you do not have a floppy disk drive, you may want to create a bootable USB memory key which will allow you to boot into a pure DOS environment. This can be very useful if you want to flash your BIOS. Here is a step by step procedure on how to perform this operation. Uses the HP USB Disk Format Tool. in Computerswith bootbootablediskdosflashfloppyhowtokeymemoryusbby 3 users