If you have tried to close a program and the window refuses to disappear, just press either Ctrl + Alt + Del and choose Task Manager, or right click on an empty part of the toolbar and select Task Manager.

Click on the Processes tab and then look in the list of running processes for the one you are trying to close. Highlight it and press End Process.

You will see a warning message like this:

If you have tried unsuccessfully to close the program down, this is when you click on "Yes".

Sometimes you will lose the bottom toolbar when you do this, but that's no hardship. Just Log Off and on again or do a restart and that will bring everything back as it should be, minus that stubborn program.