1What is the version number of the software? Is it an old version with known issues? (if you cannot get into the software to check the version, right click the icon on the desktop, on the shortcut tab choose "Open file location(Win 7). On the NBS Building.exe file that is highlighted in the next window that opens, choose properties and check the version number. Alternatively, hovering the mouse over this file will also show the version.)
2What Operating System are they on? 
3Is it network or standalone?
4If network - does the user have Read, Write, Modify permissions to the network share?
5If network - does the user have a correctly mapped drive to the network share (the same as the path the licence was unlocked to and any other working users)?
6If an installation issue - does the user who is installing have adequate admin permissions to be completing this task?
7If an installation issue from download - have they extracted the download before running the setup file?
8If a network unpack issue - are they unpacking from a client machine and not from on the server? Must be unpacked locally TO the server?
9If a network unpack issue - can they unpack to the desktop? 
10If a disc install issue - can they copy the contents of the disc to the desktop and install from there - if not - may be faulty disc.
11Data: does the same issue happen on a new test spec/prlm you create? 
12Data: can you recreate their issue with their data on your pc?
13Their PC: does the same issue happen on other installations there?