| Key combo | Function | | a href="/encyclopedia/Acorn-Computers-Ltd" title="Acorn Computers Ltd">Acorn Machines (pre-1987) | Break | Soft reset the machine (hold down Ctrl as well for hard reboot, hold down SHIFT to boot from disk) |
| Acorn Machines (post-1987) | Reset key | Soft reset the machine (hold down Ctrl as well for hard reboot, hold down SHIFT to boot from disk. On some later systems, the SHIFT key would have an opposite effect.) |
| Amiga | Ctrl + Left Amiga (or Commodore) + Right Amiga | Reboot the machine |
| a href="/encyclopedia/Amstrad-CPC-464" title="Amstrad CPC 464">Amstrad CPC 464 and CPC6128 | Shift + Ctrl + Esc | Reset (cold) |
| Amstrad PCW | Shift + Extra + Exit | Reset (cold) |
| IBM PC under DOS | Ctrl + Alt + Del | Perform a soft reboot |
| IBM PC under Windows 3.x shell | Ctrl + Alt + Del | Close unresponsive applications or (if pressed twice) perform a soft reboot |
| IBM PC under Microsoft Windows (95, 98, and Me) | Ctrl + Alt + Del | Bring up simplistic task manager (actually "Close Program" dialog) or (if pressed twice) perform a soft reboot |
| rowspan="2" valign="top" | IBM PC under Windows NT-based OS (NT, 2000, and XP) | Ctrl + Shift + Esc | Bring up the Task Manager |
| Ctrl + Alt + Del | Bring up the login screen (when pressed in login screen), or the "Windows security" dialog or (configurable on Windows 2000 and later) the Task Manager (when logged in) |
| rowspan="3" valign="top" | IBM PC under OS/2 | Ctrl + Esc | Bring up the Window List (unblocking the synchronous input queue) |
| Ctrl + Alt + Del | Perform a soft reboot |
| Ctrl + Alt + NumLock (twice) | Halt the system and begin a system dump to floppy disc |
| rowspan="2" valign="top" | IBM PC under Linux | Ctrl + Alt + Del | Signal the init process (usually configured to soft reboot) |
| Alt + SysRq + function key | Depending on the function key, performs a certain low-level function. Examples: sync (flush caches), reboot (forced soft reboot), unmount (remount filesystems readonly), etc... |
| IBM PC under other OS | Ctrl + Alt + Del | Often (but not always) configured to reboot |
| Sun workstation | L1/Stop + A | Enter ROM monitor |
| Sun workstation (serial console) | Break | Enter ROM monitor |
| rowspan="4" valign="top" | Apple II family machines | Ctrl + Reset | Enter the monitor or ROM BASIC |
| Ctrl + Cmd + Reset | Reboot the machine |
| Ctrl + Option + Reset | Enter BIOS setup, then reboot |
| Ctrl + Option + Apple + Reset | Self-test, then reboot |
| rowspan="2" valign="top" | Some Apple Macintosh computers | Cmd + Power | Enter monitor |
| Control + Cmd + Power | Reboot the machine |
| Mac OS (7 and later) | Command + Option + Esc | Force quit applications |
| SGI workstation | Left Shift + Left Ctrl + Left Alt + Keypad Divide + F12 |
| Commodore 64/128 | Run/Stop + Restore | Halt (soft reconfiguration) and return to READY prompt |
| X Window System | Ctrl + Alt + Backspace | Restarts windowing system, logging the user out if using an X display manager, kills X otherwise |
| TI-89 | 2nd + Left Arrow + Right Arrow + On | Restarts the calculator and resets all settings to defaults |
| BeOS | Ctrl-Alt-Shift and click an applications entry in the Deskbar | Kills application |