ZD620 and ZD420 Users Guide (en)
Zebra Setup Utilities: Sending Printer Commands and Receiving Data
Zebra Programming Guide
To restore the factory Zebra menus, you need to set display.root_wml property to its default and delete the custom WMINDEX.WML file. See Zebra Setup Utilities: Sending Printer Commands and Receiving Data for how to communicate with the printer. If you want, you can also use the ZSU to backup the WMINDEX.WML file before deleting it. There are likely a nu