Created for a StackOverflow answer: Can you send a signal to Windows Explorer to make it refresh the systray icons?
More commonly called the System Tray, the Notification Area can leave orphaned icons when processes are killed. These icons disappear when you mouse over them. This utility simply clears these icons programmatically. The basic work in this isn't mine, but I've updated it to work with hidden icons. For more detail see Refreshing the Notification Area (System Tray)