Windows 10

Start Menu and Taskbar

Show session options (Lock, Change user, Log off, Task Manager)

Ctrl + Alt + Del

All hotkeys for Windows 10

Start Menu and Taskbar
Open Start Menu

Win

Start Menu and Taskbar
Open Start Menu

Ctrl + Esc

Start Menu and Taskbar
Cycle through the apps on the taskbar

Win + T

Start Menu and Taskbar
Open the app pinned in the (1) position on the taskbar

Win + 1

Start Menu and Taskbar
Open the right-click menu for the app pinned in the (1) position on the taskbar

Win + Alt + 1

Start Menu and Taskbar
Show or hide desktop

Win + D

Start Menu and Taskbar
Show session options (Lock, Change user, Log off, Task Manager)

Ctrl + Alt + Del

Start Menu and Taskbar
Open Task Manager

Ctrl + ↑   Shift + Esc

Windows key
Zoom to the screen

Win + +

Windows key
Zoom out to the screen

Win + -

Windows key
Exit Magnifier

Win + Esc

Accessibility
Turn High Contrast on or off (use left Shift and left Alt)

Alt + ↑   Shift + Print Screen

Accessibility
Turn Mouse Keys on and off (use left Shift and left Alt)

Alt + ↑   Shift + Num Lock

Windows key
Open the Ease of Access Center

Win + U

Desktop
Minimize all open windows

Win + M

Desktop
Restore minimized windows

Win + ↑   Shift + M

Desktop
Minimize all windows except the selected or currently active window

Win + Home

Desktop
Maximize selected window

Win +

Desktop
Maximizes the active window vertically while maintaining its width

Win + ↑   Shift +

Desktop
Minimize selected window

Win +

Desktop
Snap selected window to the left half of the screen (If the window is already there, Windows key + Up or Down will snap it into a quadrant)

Win +

Desktop
Snap selected window to the right half of the screen (If the window is already there, Windows key + Up or Down will snap it into a quadrant)

Win +

Desktop
Move selected window to the left monitor

Win + ↑   Shift +

Desktop
Move selected window to the right monitor

Win + ↑   Shift +

Desktop
Open Task view (virtual desktops)

Win + ⭾ Tab

Desktop
Add new virtual desktop

Win + Ctrl + D

Desktop
Move to the next virtual desktop (to the right)

Win + Ctrl +

Desktop
Move to the next virtual desktop (to the left)

Win + Ctrl +

Desktop
Close current virtual desktop

Win + Ctrl + F4

Windows key
Open the Action Center

Win + A

Windows key
Open Cortana in text mode

Win + S

Windows key
Open Cortana in text mode

Win + Q

Windows key
Open Cortana in listening mode (similar to saying "Hey, Cortana")

Win + C

Windows key
Open File Explorer

Win + E

Windows key
Open the Windows 10 Feedback Hub

Win + F

Windows key
Search for PC's on a network

Win + Ctrl + F

Windows key
Open the Game Bar

Win + G

Windows key
Open the Settings menu

Win + I

Windows key
Open the Connect sidebar (for connecting to Bluetooth or Miracast devices)

Win + K

Windows key
Lock the computer

Win + L

Windows key
Lock screen orientation

Win + O

Windows key
Open presentation or projection sidebar

Win + P

Windows key
Open the Run window

Win + R

Windows key
Open the Windows Ink Workspace for scribbling on tablets or touchscreen laptops

Win + W

Windows key
Take a screenshot of the entire desktop and save it to the Screenshots folder in the Pictures folder

Win + Print Screen

Windows key
Open the emoji keyboard

Win + .

Windows key
Open clipboard history (this feature is added with October 2018 Update)

Win + V

Windows key
Open screenshot toolbar, capture an area of the screen

Win + ↑   Shift + S

Windows key
Open 'change input language' popup and switch to next language

Win + Space

Windows key
Switch to next input language

Alt + ↑   Shift

Windows key
Show desktop temporarily

Win + ,

Windows key
Open virtual keyboard

Win + Ctrl + O

Windows key
Start Speech Recognition

Win + Ctrl + S

Windows key
Start text dictation

Win + H

Windows key
Restart graphics driver (in case of problems)

Win + Ctrl + ↑   Shift + B

Similar combinations for other applications


Red Hat Enterprise (Linux)
Shut Down Red Hat Enterprise Linux System
Task

Ctrl + Alt + Del


LXDE
LXTask (task manager)
LXDE specific shortcuts

Ctrl + Alt + Del


Ubuntu
Restart the computer immediately, without saving open files
System shortcuts

Ctrl + Alt + Del


Xfce
Start xflock4
Application shortcuts

Ctrl + Alt + Del


GNOME
Power off
Getting around desktop

Ctrl + Alt + Del


Red Hat Enterprise Linux
Shut down Red Hat Enterprise Linux system
General

Ctrl + Alt + Del


Arch Linux
Reboots Computer (specified by the symlink /usr/lib/systemd/system/ctrl-alt-del.target)
Terminal: Virtual console

Ctrl + Alt + Del


Linux Mint
Log out of the system
Frequently used shortcuts

Ctrl + Alt + Del


KDE Plasma Desktop
Leave
Leaving your computer

Ctrl + Alt + Del


VMWare Workstation Pro
Shut down or, depending on the operating system, log out of the guest operating system.
General

Ctrl + Alt + Del