With the 800 connected with the supplied cable to a usb port on your computer it will appear in the "my computer" as a drive with a letter assigned to it. But you can't access it except when the scanner is off.
So, with the scanner off, right click on that drive (It will have a volume label of "EZSCANDG") and then select "properties" on the dropdown menu. The resulting window will tell you what you want to know.