I've spent many hours working on this issue for my parents and I'm out of ideas at this point. On their home PC they are running Windows Vista. They just purchased an OfficeJet 6500 Wireless All-In-One. Even though it has wireless capabilities, I have the All-In-One plugged directly into the router.
I found the update on HP's site that allows you to scan using the Control Panel on the printer itself, however, my mom is wanting the capability to scan using her Acrobat 9 Pro. When you use Acrobat to Create PDF - From Scanner - Black and White it immediately tries to open the HP Scanning software, then I get an error message that says tells you to try rebooting the PC, turn the printer off and on and try reinstalling the Photosmart software. That is followed by an error that says Acrobat could not communicate to this device.
I've done many searches and it seems as though this problem has been an issue since 2008, but I have yet to find a solution. I've tried removing all HP software and only reinstall the printer and scanning drivers, but that didn't work either.