1st Removable Device
The option description:
Gives the chance to specify the exchangeable disc storage (the disk drive, drive ZIP etc.) on which first of all it is necessary to search for an operating system. The option is actual, when such drives are connected to the computer some.
In most cases at a choice of this option (pushing it of a key [<Enter>]) you get to the additional menu where it is already possible to select the order of inquiry of exchangeable disc storages immediately.
Other options identical to destination: