Many printer issues can be resolved by resetting the printer to factory defaults, In this case, a printer would not release the error message “Print Head not installed or missing.” The printer was an HP Office-jet Pro 8610. Once the print head was cleaned, re-seated and locked down the error message remained no matter how many times we followed the steps outlined.
Finally, we reset the printer to factory defaults and it worked. The error message went away and the printer ran flawlessly. The instructions to reset to factory defaults is online, but in this case you would access the reset menu by tapping the arrow key on the lcd screen four times. You then have the option of which reset to use.
In our case a partial reset failed and only the full reset did the trick. Keep in mind any settings you had will be gone. Any wireless connections will have to be reset as well.