Have a Canon Pixma MG6450 which has decided to refuse to be able to scan direct from the device either via USB or Wireless, shows PC-Direct as only option (Doesn't work either) uninstalled the drivers, used Revo Uninstaller to remove the software, reinstalled and last part of a laborious 20 minute install throws up a "Could Not Create Port:0023 error, i can get Windows Fax and Scan to use the scanner as a TWAIN device but nothing from the device itself, Canon suggest i use the IJ Network Utility but this does not install from the full software installation, ran separately but does not recognise the printer/scanner - i can wirelessly or via USB print just not scan.
Hacked some of the registry out relating to the device but now out of ideas, main reason it is still an issue is Windows Fax/Scan does not give scan to email or scan to PDF...