Editing Multi-booting (section)

===Number of operating systems per storage device===

In a multi-boot computer each of the multiple operating systems can reside on its own storage device, or some storage devices might contain more than one operating system in different partitions. The boot loader in or loaded by the [[Master boot record|MBR]] displays a menu of logical drives and loads the selected boot loader from the [[Volume boot record|PBR]] of that drive.

An example of a computer with '''one operating system per storage device''' is a dual-booting computer that stores [[Windows]] on one disk drive and [[Linux]] on another disk drive. In this case a multi-booting boot loader is not strictly necessary because the user can choose to enter BIOS configuration immediately after power-up and make the desired drive first in the boot-order list. However, it is more convenient to have a multi-booting boot loader on one of the drives, set BIOS once to always start booting from (i.e. load the boot loader from) that drive, and then allow the user to choose an operating system from that boot loader's menu. No special disk partitioning is necessary when each operating system has its own dedicated disk drive.

An example of a computer with '''multiple operating systems per storage device''' is a dual-booting computer that stores both Windows and Linux on the same disk drive but where the BIOS in the system does not let the user boot individual drives and partitions. In this case a multi-booting boot loader ''is'' necessary. Also, the disk must be partitioned to give each operating system its own partition on the disk drive. This is necessary because each system has its own set of files and operating instructions. Also, when a completely separate operating system is used partitions may need to be formatted to a different format. For example, if a user intends to install both [[Windows]] and [[Linux]], then the Windows partition will be most likely formatted in the [[NTFS]] format as Windows cannot run off of [[ext4]], and the [[Linux]] partition will most likely be formatted in the ext4 file format as Linux cannot run off of NTFS. However, if a user intends to dual-boot two versions of [[Windows]] (i.e. [[Windows 7]] and [[Windows Vista]]) or two versions of Linux (i.e. [[Linux Mint]] and [[Ubuntu Linux]]), then the same file system (e.g. NTFS or ext4) can be used across both drives and partitions.