Seeing printer error 79 could be the result of corrupt/outdated firmware, an issue with the print server, external app interference, or other factors. If you are experiencing this issue, first check your HP printer to confirm everything is functioning properly. Also, perform a reset to fix minor software glitches. If that does not help, then follow these two solutions.
First, make sure that the HP printer is connected to your computer.
Go to the support.hp.com website to download the drivers.
In the product type section, choose Printer.
Under the Identify your printer section, search for and select your HP printer model.
Now, you should go down to the firmware section and download the latest update.
Next, double-click on the downloaded file and check the status of your printer.
You should connect the printer and computer to a USB cable if your network printer isn’t detected.
Then, you need to wait around 20 minutes and then choose the Refresh button.
Choose Update to move forward.
After that, enable the firmware update to complete (You should not turn off the printer during the process.)
At the bottom right side of your PC taskbar, double-click on the printer icon.
Select and right-click on the print job you need to cancel.
Then, choose the Cancel button.
On the open prompt, choose the Yes option for confirmation.
After using these two solutions, see if your HP error 79 is resolved. If the error is not gone, then try to get your hands on professional help and guides.
Source:- HP Printer Error 79 [Fixed]