Multi-booting

Multi-booting is the act of installing multiple operating systems on a single computer, and being able to choose which one to boot.

Another reason for multi-booting can be to investigate or test a new operating system without switching completely.

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.

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.

They use configuration files in /boot to control their selection menus, The OS/2 Boot Manager must be installed in a primary partition.

One popular multi-boot configuration is to dual-boot Linux and Windows operating systems, each contained within its own partition.

Windows does not facilitate or support multi-boot systems, other than allowing for partition-specific installations, and no choice of boot loader is offered.

Commonly installations proceed without incident but upon restart, the boot loader will recognize only one of the two operating systems.

The MBR boot code can be backed up and restored with dd, available on System Rescue CD.

[3] Operating system selection at boot time consequently depends on the bootloader configured within the primary partition that has the boot or "active" flag set on its partition table entry, which could be a bootloader of DOS, OS/2, eComStation, ArcaOS[4] or BSD, in addition to Linux or Windows.

Boot Camp allows owners of Intel-based Apple Macintosh computers to install Windows XP, Vista, 7, 8, and 10 on their Macs.

Apple does not support non-Windows partition formats or drivers so therefore configuring other operating systems is not directly possible through Boot Camp itself.

However, any operating system which can utilize the BIOS emulation of Intel Macintosh can be made to work, including non-XP versions of Windows.