When I prepare a document in Word for instance, and then go to fax it with documents in the feeder tray or on the glass, I get the message, Printer Scanner not Available. Engineers at H-P (OfficeJet Pro all-in-one 8500) can't even fix this problem.
Alright, if the engineers at HP can't fix the problem, there isn't a lot for us to do.
Even though, I would recommend you to uninstall all the existing driver/software/features of the printer, it means from the "Device Manager" and from the "Add or Remove Software" tool, and from any other place that comes up in your mind.
After wards unplug the printer cable of the computer (LPT/COM/USB) and look if there is something wrong with the connections/pins (more likely with the LPT/COM).
And than try to install everything from top, like if you just bought it.
I think it can be a reasonable thing to do, before throwing it to the garbage (Hopefully you will take it for recycling), or taking it to the HP laboratories.