Disks and boot devices
Another fundamental configuration item required in BIOS settings is the selection of storage devices. Newer systems are able to detect and properly configure much of this hardware automatically. However, older BIOS versions require manual configuration. This may include the selection of floppy disk sizes and disk drive parameters.
Most PCs have at least three bootable media types: an internal hard disk (IDE or SCSI, or perhaps both), a CD-ROM drive (again IDE or SCSI), and a floppy disk. After initialization, the BIOS seeks an operating system (or an operating system loader, such as the Linux Loader [LILO]) on one or more of these media. By default, many BIOS configurations enable booting from the floppy or CD-ROM first, then the hard disk, but the order is configurable in the BIOS settings.
In addition to these default media types, many server motherboard BIOS (as well as high-end system motherboards) support booting from a network device such as a NIC with a bootable ROM. This is often used when booting diskless workstations such as Linux-based terminals.