Can't print and only displays the Fax Dialog when trying to print

Question

HP Office Jet 4500 All in one
When we setup our new printer it worked fine until now when I try and print any Word, Web, or Picture the Fax Dialog comes up instead to send a fax. I don't recall changing any settings. How can I resolve this?
There are 2 printer types showing in Printers and Devices. I have tried changing the deault printer, but nothing seems to work.
HP Office Jetg510g-m &
HP Office Jetg510g-m fax

Answer 1

Remember, this is an Apple user to user help site, so few us may be experts with HP printers. OSX automatically installs the right printer software, you really don't have to go to HP to do that. In fact, I trust Apple to get it right more than HP.
That being said, the very first thing you need to do is to make absolutely certain that the printer is linked into your WiFi network. Again, we're not HP experts here, so you'll have to do that one yourself, by reading the instructions. Once your printer is connected to the network, then go to your iMac's System Preferences>Print&Scan. On the left hand side is a +. Click on that, and it should find your printer, if it your iMac and your HP printer are on the same exact WiFi network.