I posted this in the HP forums, too. Just trying to cover main bases of where people might look for help.
I just bought the HP 8600 OfficeJet and was having massive problems with the scanner function. I have two laptops. The Toshiba 640 (special build) is running Windows Ultimate. The Toshiba Portege R835 is running Windows 7 home. Both printed wirelessly
just fine.
Both had scanner issues from both the scanner to the computer and the computer to the scanner. The scanner would start the scan function and then the error message would appear that the wireless system was not working.
BTW when I first set the printer up and it connected to the network it never asked for the network key, and I had to add that manually.
Spent about an hour with tech support. He did something on the other computer involving telling the WIA to troubleshoot. An error message came up that it couldn't be done and was shutting down. Since I was working on my computer and he was working on
the other computer (remote connection) I didn't see what he was doing.
However, then I went to the website
http://h20000.www2.hp.com/bizsupport/TechSupport/S
I downloaded the HP Print and Scan Doctor, it hung at WIA for a few minutes then indicated it was just fine. It completed with green check marks by everything. Then amazingly the scan function worked just fine. On both computers. I didn't do the diagnostic
on the second one, just restarted it, and it now worked.
I don't know if it was the diagnostic tool alone that solved the problem, or what the tech did in conjunction with the diagnostic tool that solved the problem.
Long story short, try the diagnostic tool.