Before anyone autoposts links to things, this is NOT "will FSX run on Windows 7".
My question is whether running the Microsoft upgrade from Vista to 7 will cause any problems with my FSX installation. Theoretically, the upgrade is designed to change the operating system with all currently installed software sitting there happily, but as we all know these things don't always go smoothly! I'd rather not have to re-install FSX due to the large number of downloaded addons, so before anyone suggests I'd be better off just re-installing it, that's not the favoured option.