Scan problem

The scan function in Windows Fax & Scan doesn't work. The dialog opens, but clicking on scan..nothing happens. I am using professional. I have another Win 7 computer on the same network using Win7 Home edition that does work properly. I am using a new HP all-in-one on a wireless network. I would normally use the HP software, but it seems to me that the problem might be a problem with a windows driver. (I didn't have this problem for the first 3 months I had this HP unit).

Check to see if there are any driver&software updates for your HP printer.

I have downloaded the driver (OJ8500_A910_231) and that didn't help. Remember, I have a second PC on the network that uses the same software and works fine. It doesn't seem to be a network problem; I can print to the HP printer fine from both PC's. I have deleted all the programs associated with the printer from the PC with the problem and re-installed several times and seen no change. Also, the Windows Fax & Scan program in the "good" PC works with the HP unit.