Every time I've tried to update to version 9 of iTunes + Quicktime i get about 4 instances of error messages saying:
The installer has encountered an unexpected error installing this package. This may indicate a problem with this package. The error code is 2503.
it then proceeds to give this message for error code 2502 and does this for both errors another 4 times (5 times total) during the attempted installation before telling me that it was unable to complete and the original version would be restored.
i tried downloading the exe and had the same problem there. So i then attempted to remove all of iTunes 8 and quicktime through the add/remove function in windows, and got the same error message! so whatever it is has to do with iTunes 18.104.22.168 as well as quicktime. i can't get rid of either of them. and help would be great