In a proper installation of an average software, its executables would be in the program files folder; its user data in the user's application data folder; it's non user specific data in the all users application data folder; and it should usually be able to run under non-administrative privileges. These guidelines could easily be ignored on XP, but they are an issue on Vista and 7 due to UAC.

We're on the verge of releasing a major version of our software. It's a CMS, used by our clients as their main work tool, and their IT staff are well familiar with it. If we want to be fully compatible with Windows 7, we have to make quite a few changes, and we're already on a tight schedule.

Question is: we can easily have our clients install our software outside of program files, or have them run it as administrators. I think it's wrong, but I need some ammunition: why should we install on program files, with all the limitations that come with it?