Some times applications become non-responsive due to defects in its software. KDE makes it easy to close them using the standard close button present at the top right corner of the window.

Just press the X button at the top right corner as you close any other application. If the application is responsive it will be closed normally. Otherwise KDE waits for a definite time for the application to close when the X button is clicked. If the window doesn’t close with in that time, KDE will show you a dialog prompt that will let you terminate the application forcibly.

There is another way if you don’t want to wait until KDE shows you the dialog prompt to close the window forcibly. To use this method,  you can terminate any window without any delay. It is like killing an application or a process using “kill -9″ option.

First press Ctrl+Alt+Escape sequence that will turn the mouse cursor in to a skull like (danger signal) cursor. Now you move the cursor on to any window which you would like to kill and click on it. Be careful while clicking because if you click on any other window the corresponding application will be killed.