I spend most of my spare time testing new linux based distros so I have already burnt a huge stack of Live CDs which also cost a lot of money. While having them in DVD format was good enough for my needs, most of them where scratched and useless so I started researching for a new way to test my beloved distros among different computers.
Then I found that I could write my iso files in a usb flash drive and boot from that key. While most of new pc models were capable of booting off a usb drive, some old pc models (on which I usually test ultra-lightweight Linux distrubutions such as "Puppy Linux") cannot boot from usb keys.
However, there is a way to bypass this awful motherboard restriction and boot from usb flash drives without modding the B.I.O.S.(!!!!do not try this method unless you really know what you are doing!!!!).
In this instructable, will bypass this restriction using a linux based bootmanager. This bootmanager can be written on a disk or on a floppy disk.