It's working! What i did:- A complete clean installation of Windows 7 - 64 bit- Download all possible updates of Microsoft Windows Update- Format one partition in chunks of 64 KB (Recomended if you are using this for FSX only)- Install FSX de Luxe RTM (By opening the explorer on DVD and execute the installation as administrator)- Install SP1 (right click - execute as administrator)- Install SP2 (MSI)- After the installation i ran FSX, activate it and then quite so it had to write the FSX.cfg once.- I made sure the FSX.EXE will be executed as yes... administrator.- Install the PMDG package- Install the liveries- Run FSX- And than choose the PMDG B737/800 - meanwhile accepting the DLL's and completed the activation. --- This is working. And now i am careful making an ghost image of it and a restore point in windows before installing other software or making adjustments in the configuration of FSX--- I know that IVAP (IVAO software) is working pretty crap and they have never test this on a windows 7 (64bit) environment. It needs Runtime Libraries of Visual C++ 2005. (PMDS is using 2008 files). The best thing for me is to avoid this installation in FSX and run this from an other machine. Ooh and yes.. There's one known issue.. and that is when you exit a flight it has the APPCRASH. But it looks like a lot of people dealing with and i think this will be solved in the next hotfix. Probleemhandtekening: Gebeurtenisnaam van probleem: APPCRASH Naam van de toepassing: fsx.exe Versie van toepassing: 10.0.61472.0 Tijdstempel van toepassing: 475e17d3 Naam van foutmodule: PMDG_737NGX.DLL Versie van foutmodule: 1.0.0.0 Tijdstempel van foutmodule: 4e3afb98 Uitzonderingscode: c0000005 Uitzonderingsmarge: 00173db7 Versie van besturingssysteem: 6.1.7600.2.0.0.256.1 Landinstelling-id: 1043 Good luck.