To kill a process, use "pprocess" under "System" or open a terminal and type:
killall
followed by the name of the program.. IE:
and hit enter.killall mplayer
Some Pups have "kill" as a right click menu item, to use on the taskbar..
You can also start a program this way, by name, and use the terminal to chase errors...
BTW the Linux equiv to ctrl-alt-delete is ctrl-alt-bkspc
which will exit the Xserver to a console..
Enter
to return to the desktop...xwin
For fun, open a terminal and enter
xmessage I wrote this!!!