I was unable to install current PMDG for 777 and 737 for steam on my G drive. I have FSX on C drive and steam on G drive. Do I have to uninstall FSX PMDG on C drive in order to later install both on C and G drive. I am only offered to uninstall or repair when trying to install to STEAM on my G drive. Thanks Tim. I did the simconnect  thing for steam as recommended in your current installer.

Do I have to uninstall FSX PMDG on C drive in order to later install both on C and G drive

Yes. After you uninstall the FSX version, next time you run the installer you will get the option to install both the FSX and FSX-SE versions

Great. Thanks for the response.