Windows does not have a
force-quit shortcut key combination. But many programs respond to different key combinations regardless, such as ALT-F4, CTRL-W, or a custom combination specifically for that program.
Alternatively, if it is just one program you want to be able to force-quit by the press of a button (because ALT-F4 does not work) you can use the commandline taskkill /f to force close an application. By creating a shortcut (and optionally assign it a shortcut key) you can close the program by either launching your shortcut or by pressing the shortcut key.
Lets assume the program you want to close is Internet Explorer. Your shortcut would be this:
The application is:
C:\Windows\System32\taskkill.exe /f /fi "imagename eq Iexplore*"