Reboot

Early electronic computers (like the IBM 1401) had no operating system and little internal memory.

This process was likened to an old saying, "picking yourself up by the bootstraps", referring to a horseman who lifts himself off the ground by pulling on the straps of his boots.

[6] The Windows NT family of operating systems also does the same and reserves the key combination for its own use.

[7][8] Operating systems based on Linux support an alternative to warm boot; the Linux kernel has optional support for kexec, a system call which transfers execution to a new kernel and skips hardware or firmware reset.

[citation needed] Outside the domain of IBM PC compatible computers, the types of boot may not be as clear.

This can be achieved by either applying a reset, by cycling power, by issuing the halt -q command in most Unix-like systems, or by triggering a kernel panic.

Such crashes may occur due to a multitude of software and hardware problems, such as triple faults.

For example: the Sysinternals BlueScreen utility, which is used for pranking; or some modes of the bsod XScreenSaver "hack", for entertainment (albeit possibly concerning at first glance).

Malware may also simulate a reboot, and thereby deceive a computer user for some nefarious purpose.

[6] Microsoft App-V sequencing tool captures all the file system operations of an installer in order to create a virtualized software package for users.

"Fast Boot") which can cause problems (including confusion) for users accustomed to turning off computers to (cold) reboot them.