Icon

If you are referring to the Windows Task Bar, it depends on where you want to place the Icon.

If you want to place a shortcut in the Quick Launch Box (next to the start button) you can drag any shortcut from the desktop into the Box, and a shortcut will appear. If you want, you can then delete the shortcut from the desktop.

If you are looking to add an Icon in the System Tray (on the far right), that is a more involved manner. Most of the Icons in the System Tray are for programs that keep a small portin of themselves running all the time so that you can launch the program quickly.
I recommend only having necessary items in the Tray, as each one uses system resources.

If you are talking about adding a custom Icon to the Menu orToolbar of an application. That is even more involved, and varies somewhat from application to application.

simply call jFrame.setIconImage(new ImageIcon("foo.gif"));

it only works for swing JFrame ...

cheers

s.okujava