Symptom
The Desktop Printer Menu extension is installed, but there is no Desktop Printer menu in the menu bar.
Solution
An implementation of the Desktop Printer menu is provided by the Limited and Panels environments. As a result, the Desktop Printer menu extension is not displayed in the Finder environment.
If you are not using the Multiple Users feature, use the Extensions Manager control panel to turn off the Multi-User Startup extension and the Desktop Printer menu will become available in the Finder.