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. The term dual-booting refers to the common configuration of specifically two operating systems. Multi-booting may require a custom boot loader. Multi-booting allows more than one operating system to reside on one computer; for example, if a user has a primary operating system that they use most frequently and an alternate operating system that they use less frequently. Multi-booting allows a new operating system to configure all applications needed and migrate data before removing the old operating system, if desired. Another reason for multi-booting can be to investigate or test a new operating system without switching completely. Multi-booting is also useful in situations where different software requires different operating systems. A multi-boot configuration allows a user to use all of their software on one computer. This is often accomplished by using a boot loader such as NTLDR, LILO, or GRUB which can boot more than one operating system. Multi-booting is also used by software developers when multiple operating systems are required for development or testing purposes. Having these systems on one machine is a way to reduce hardware costs. Multi-booting also allows a user to switch between private and work dedicated systems to maintain access integrity and separation between the two user environments, even if the same operating system is used for each of them. A possible alternative to multi-booting is virtualization, where a hypervisor is used to host one or more virtual machines running guest operating systems. In an OS/2 dual-boot configuration, the C drive can contain both DOS and OS/2. The user issues the BOOT command from the DOS or OS/2 command line to do the necessary copy, move and rename operations and then reboot to the specified system on C:. Other systems provide similar mechanisms for alternate systems on the same logical drive.