I had a problem with a HP LaserJet 8620. No matter what I did the HP printer software would not communicate with the printer. And because of that scan did not work. A complete uninstall of driver an d HP software did not help. And even though everything had been uninstalled HP Print and Scan Doctor stilled showed two LaserJet 8620 installations.
Luckily Kyocera has made a great printer removal program called Kyocera Deleter for Printer Driver. This program can be used to find and delete a printer from your computer
After the old printers was removed I could reinstall the HP printer software and everything was working again.