Boot disk
<operating system> The
magnetic disk (usually a
hard disk) from which an
operating system kernel is loaded (or "bootstrapped").
This second phase in system start-up is performed by a simple bootstrap loader program held in
ROM, possibly configured by data stored in some form of writable
non-volatile storage.
MS-DOS and
Microsoft Windows can be configured (in the
BIOS) to try to boot off either
floppy disk or
hard disk, in either order.
By default they first check for the presence of a
floppy disk in the drive at start-up and try to use that as a boot disk if present.
If no disk is in the drive they then try to boot off the hard disk.
Some operating systems, notably
SunOS and
Solaris, can be configured to boot from a network rather than from disk. Such a system can thus run as a
diskless workstation.
