Zitat

Windows VISTA users will need “elevated” administrative privileges in order to Register. To obtain these please run FS using the right-click “Run As …” option to run as the administrator. You don‘t have to always run FS in this way, only to enter the Registration. Note that under Vista FSUIPC‘s Log file shows FS2004 as running on Windows XP SP2, not Vista—I don‘t know if this also applies to earlier versions of FS, but it probably does. It looks like Vista automatically puts versions of FS prior to FSX into a sort of "compatibility"– mode, even when this isn‘t manually selected in the Properties.