This is a fix / solution for the 79.00FE error as displayed on a HP 8100dn printer, however, I understand that this can also apply to the 5Si, 8000, 8150 series printers. When this error is encountered, the printer will become unresponsive, but may still be accessible via the web GUI.

79.00FE usually means a that the jet-direct card is receiving information that it cannot interpret (PDF files seem to often be the culprit). Here is some documentation to back up that claim HP’s 79.00FE Troubleshooting Guide. If my quick fixes don’t work, be sure to review it.

Quick Solutions:

1) Turn off the HP printer. […]