flash drive boot problem

i was trying to boot from a flash drive on my computer but when i do it says no boot table or something like that how can i fix it
note: im trying to boot pendrive linux 2008

your flash drive isn't bootable

i thank i did it all corectley, how do you make it bootable?

you recreate the partitions and set one as bootable.

??? how do i do that

not all motherboard bios allow you to boot from usb devises

i have the bios but i need to make the usb bootable