According to HP, restoring the factory-set defaults on your printer will not reset the page count, tray size, or language.
To restore your HP printer to factory-default settings, follow these steps.
1. Turn the printer off. Disconnect the power cable from the printer for 30 seconds and then reconnect.
2. Turn the printer on while you press and hold the Resume button for 10-20 seconds. The Attention light turns on.
3. Release the Resume button. The Attention and Ready lights cycle while the printer restores factory defaults.More details: The Ultimate Guide To Reset HP Printers?