First, disconnect the printer, turn it off and unplug it from both power and computer. Leave it that way throughout the following, until you are instructed to connect it up again by the installation software routine (or, at least, by that routine having completely ended and finished and exited etc.)
So: turn off, unplug, unplug your printer.
Go to your computer, to the Start button, then to Control Panel, and remove all entries for your printer and its series in
View Devices And Printers,
under the Hardware category) by clicking on each icon for the HP printer and deleting it.
Then, reboot your computer: shut it down and start it up again.
Then, go to
and download the
HP Officejet Pro 8630 e-All-in-One Printer series Full Feature Software and Drivers
and once downloaded, install them.
And by and by, try the printer again. I hope that cures it!