For an HP Officejet Pro 8500 Wireless printer used on a Windows7 64 bit system, you have to download all the software and
drivers for the Windows 7 64 bit system from the HP website.
This will not necessarily solve the problem, because Miscosoft is having a problem with the Print Spoolers turning off by themselves.
You need to go to the START button, type in "services" , then look for the "local services" file, then find "spooler" and look on the left side and hit the "start" or restart button (this will restart the spooler), wait a few seconds and then try and print something.
It will work, yet you will probably have to do it over and over again each time you restart your computer since microsoft and HP have not gotten a patch ready yet.
Good Luck.