Here is what I have in Digital dashboard. It gives the total number of Not scanned computers but it doesn't provide a link to show which computers Not scanned.
Operating systems Microsoft Windows 7 Enterprise 1 Microsoft Windows XP Professional 226 Microsoft Windows Server 2003 Enterprise 1 Not scanned 39
If you click on the not scanned computers and go to the "error" tab you will get a detailed error description of why the computer could not be scanned.