Abstract: A method for specifying an operating system (OS) file to use in a computing system after a system reboot begins by copying at least one new OS file to a system disk. An OS file to be installed is selected from the new OS files on the disk. The system is booted into the selected OS file, the selected OS file becoming the currently running OS on the system. A boot pointer on the system disk is updated to point to the selected OS file, such that any subsequent reboot will be into the selected OS file.

Abstract: A method for upgrading an operating system (OS) on a computing system without system interruption begins by installing an upgraded OS. A boot pointer is set to point to a memory location that points to the upgraded OS. The computing system is booted into the upgraded OS, and the upgraded OS receives and processes commands. The boot pointer on the computing system's disk is updated to point to the upgraded OS if a user instructs the computing system to make the upgraded OS permanent, whereby the OS is upgraded without interrupting the computing system. The OS may also be upgraded automatically, without instruction from the user, if predetermined criteria are satisfied.