The usual straightforward way is to run Task Manager with ctrl-shift-esc, then choose the Firefox process in the Applications tab and pressing del to kill it (or clicking the "End task" button).

(This is Windows 7; it looks somewhat different in different versions.)

The usual straightforward way is to run Task Manager with Ctrl+Shift+Esc, then choose the Firefox process in the Applications tab and pressing Del to kill it (or clicking the "End task" button).

(This is Windows 7; it looks somewhat different in different versions.)

The usual straightforward way is to run Task Manager with ctrl-alt-del, then choose the Firefox process in the Applications tab and pressing del to kill it (or clicking the "End task" button).

(This is Windows 7; it looks somewhat different in different versions.)

The usual straightforward way is to run Task Manager with ctrl-shift-esc, then choose the Firefox process in the Applications tab and pressing del to kill it (or clicking the "End task" button).

(This is Windows 7; it looks somewhat different in different versions.)