Barry,
I had a combatability problem with HP products. HP released a patch to correct the problem. I downloaded the patch for my printer and it was only a few megabyte. From memory it was not the download you mention (193mb is a big download). This download is a complete driver download for all HP items. I would enter the HP website and search a compatable download for your scanner.
FOOTNOTE: Barry, I typed in the following in Google search and got numerous hits regarding incompatability with HP scanners - ‘Windows 7/HP compatability problem’. Came up with this response -