To determine the serial number, exit to a DOS (command) prompt, and type the command "dir c:\ /p" (without the quotation marks, of course). This will display the first page of a directory listing for the root directory of the C-drive. The second line displayed will contain the serial number, like this:

Volume Serial Number is 1A2B-C3D4

That is the number that APPX requires, but it will be reformatted when entered on your license and when displayed by APPX. APPX makes three alterations to the serial number:

Add a leading zero and hyphen

Change all upper-case letters to lower-case

Remove the hyphen between the two groups of characters

So, the serial number 1A2B-C3D4 will be entered and displayed in APPX as 0-1a2bc3d4.

Note: A foolproof way of determining that you have the correct serial number on any platform is to start APPX. Without a valid license, the system will display the serial number it finds on the machine.