# Knowing Knoppix/Recovering from freezes

It is possible for the X Window System, the K Desktop Environment, or an
individual application to \"freeze up\". This section explains what to
do if that happens.

## Getting rid of an individual application

The most common situation is to have a program that just doesn\'t seem
to want to go away. Even when you click the close button on its window,
it still won\'t disappear. To get rid of it:

1.  Press Ctrl+Alt+Esc on the keyboard.
2.  The pointer will change into a skull and crossbones.
3.  Point anywhere inside the window that you want to get rid of.
4.  Click the left mouse button.
5.  The errant program will be killed.

## Restarting the X Window System

If many programs or your entire graphical environment seems stuck, you
can try to restart the X server entirely.

Pressing Ctrl-Alt-Backspace kills X. The display manager should bring it
back up again.

An alternate way to restart X in Knoppix is to:

1.  Press Ctrl+Alt+F2.
2.  Type this command, then press Enter:\
    `init 2`
3.  You will see the message \"X Window System shut down\". This will
    also end the K Desktop Environment and all its open applications.
4.  Then enter:\
    `init 5`
5.  The X Window System will be restarted. The KDE desktop will appear
    again as it did when you first started Knoppix.

