I had to reinstall the 727-100 base pack and the 727-200 expansion model. The installation never ask me the order number like it is suppose to do so from what I read in the user manual. The installation progressed without any errors. After the reinstallation, none of the overhead panel buttons works and I'm not able to turn on the battery from the engineer upper panel. The battery cap doesn't lift up. I guess the problem must come from the unsual reinstallation behaviour. I don't know what else to do to reinstall the product correctly. Can someone tell what I'm doing wrong in the reinstallation process. Thank you for your help.

The reason you were not asked to activate the 727 again is because the Windows Registry entry for the 727 is still there. Try doing a "Repair". Run the installer (use the "Run as administrator" option if you are using Vista/Win7/Win8) and select "Repair" when given the choice to "Repair" or "Remove" it. After it finishes, start FSX and test it to see if it's working correctly.

If you are still unable to work the buttons, you should try a full uninstall/reinstall (KB #685), which includes deleting the 727 entry from the registry (see image below). Check-in to Your Profile > Product > Customer Support > Search KB or Submit New Ticket, search for KB #685 (without the #) and follow the instructions.


http://captainsim.org/yabbfiles/Attachments/CS727_registry.jpg
This image shows the registry entry for the 727-100 Base Pack (721PRO_FSX), as seen in my Windows 7 64bit registry.
Directly below that, is the entries for the -200 (722_FSX) and the Freighters (727F_FSX), in case you need to remove them as well.