I have a quite old HP LaserJet 4 printer which worked fine before I did some recent updates to the host computer. It still has Windows 8.1 but now the 64 bit version because the new host has more memory than the old, before it had the 32 bit version of the same OS. I've downloaded a driver, hplj4_ps_en which Windows says is an Application, but when I try to run it, a message comes up that I cannot run this app. How do I install the driver?
