The following article may explain why you cannot boot from a floppy disk:
(Taken from: http://www.experts-exchange.com/Operating_Systems/WinXP/Q_21037513.html)
This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility.
Plug in the external drive you wish to encrypt:
Make sure all previous data on the drive has been …
This Micro Tutorial will teach you how to reformat your flash drive. Sometimes your flash drive may have issues carrying files so this will completely restore it to manufacturing settings. Make sure to backup all files before reformatting.