Just purchased Los Angeles V2 to add to my CYVR and KJFK V2 with GSX to FSX additions.
I've just spent the last three hours trying to register it with the serial number but each time was unsuccessful. When I hit the Register Now key, nothing, no message box, nothing on the desk top.
Anyway to cut a long story short, I closed FSX down again and started it up from the FSX icon on the desk top (I have always started FSX via REX with the "Fly Now" button). This time the registration box came up and LA V2 is installed and active.
Just thought I'd mention it here in case another user has the same problem.
A Merry Christmas to all.