I was ready to give it all up and buy a Brother. I had installed, removed, reinstalled, ran Scan and Print Doctor, ran it again, deleted temp files and nearly starter tearing what's left of my hair out, when I remembered:
The last time I had reinstalled the software for my terrific HP 4630, I had been offered the opportunity to print via the home network or the USB. My PC had always been the "land line" of my home network. It is connected to the LAN by a CAT 5 cable and to the printer with a USB cable. In the past, this worked out fine because all my previous PC's had no wifi connection. BUT my latest PC, upon which I am fighting to load my HP 4630, has a WIFI connection built into the motherboard. It was acting in conflict with the USB connection to the printer. After all, the scanner was working through the USB, and the fax icon was present in the devices and printers list. But the printer wasn't there and the printer wouldn't work from my PC, though it did fine with my wife's iPad and Notebook.
So I removed the previous installation of the 4630, pulled the USB from the back of the printer, rebooted the PC and reinstalled the printer software. Before completion of the installation, the installer asked if I wanted to converet my previous USB connection to a wireless connection. I agreed. Was asked to plug the USB back in, then in a few moments was instructed to disconnect the USB. And behold, when the printer said itwas ready this time, it was truly able to print.
So the moral is, if your PC has WIFI use that network to run the printer!!!