I have a new G7020 and setup everything from the ij.start.canon site.  I cannot get it to scan by hitting the scan button on the front panel.  It is connected to my PC via USB.  When I press the start button, I get a popup on my Windows 10 PC that says "Canon G7000 series", "Save to PC", and has a box that says "Select the program to launch for this action:", but it is blank.  There are no programs to choose.  I am able to scan using the Canon IJ Scan Utility just fine, but I cannot use the buttons on the scanner.