CTD while loading PMDG 747-400

Hello all,A few days ago I bought the box version of PMDG 747-400.But I can't use it for some strange way.This is what the problem is : After I installed the product and go to my FS9 and selected the 747 I crashes to my desktop when it's almost loaded in Flightsim.I don't know why but I did a re-install and keep having the same problem. So at this point I can't fly the 747 at all because it crashed even before it is loaded. And I only have this with the PMDG 747. I also have the PMDG 737 (box version) that one is installed first.Hope someone can help me with this.Regards,Guy