If a program locks up, you can force quit it a number of different ways.
The System Monitor Way
If you’re at all familiar with the Windows task manager, you’ll figure out how this works pretty quickly. Go to
System > Administration > System Monitor. Switch to the Processes tab if it doesn’t go there by default. Locate the program you want to close; all the programs are shown by name and they also have a tiny icon so you can generally identify what they are. Once you find the application you want to kill, select it by clicking on it. Then hit end process.
If you’re trying to close Firefox for example, you will see Firefox and close it. You’ll probably also see firefox-bin and that needs to go too.
The Force Quit Menu Way
If you’re familiar with Mac’s force quit menu, this might be more similar than the first method. To access this, right click on the bar at the top of the screen, where the time and Applications menu is. Click Add to Panel. This will bring up a window. In the search box, search for Force Quit. Once you find it, click the add button. Then close the window. Now click on your new launcher icon and Force Quit will tell you you can now click on the Application you want to force quit.
New! The xkill Way
If you have Ubuntu 11.04 or later, you might be running on Unity, that Gnome fork that doesn’t really work. I haven’t used it more than in brief testing, but when I needed to kill something, I liked using the
xkill method. Simply use
ALT + F2. Then, type
xkill and simply click on the window you need to force quit. This is very similar to the Force Quit Menu Way but doesn’t use a launcher. I couldn’t use the traditional method in Unity, so this method works.
Hope that helps.