747 FS9 version R12 - Crash when loading

Could somebody confirm that the FS9 upgrade coming with the FSX version cannot be installed unless the 747 Freight version is previously installed ?Having installed this version (R12) under VISTA-64, the 747 cannot be loaded anymore (FS9 terminates), even when starting first with the Cessna and then selecting the PMDG 747. Before installing R12, it was working without issue. Other version of 737-900 loads normally and so does the FSX version.Also what would be the best method to uninstall version R12 without affecting the other versions (FS9 + FSX) installed ?Thanks in advance,