We are writing an installer for our Windows tool. As our tool uses an updater (wyUpdate) and we want that users WITHOUT Administator rights can performs updates. Which is the right directory to install the app to? The standard C:\Program Files requires Administrator rights, so we have discarded this option. After reading a bit on the Web, we have chosen AppData, i.e. C:\Users\USERNAME\AppData\Local.
Is this best practice? Or should we use another directory?
If you do not want to allow your users to mess with the installed program, you have to install it to a folder that needs Administrator privileges.
To allow an automatic update of such application, you need to develop/install a service that runs with Administrator privileges, which will update the installation. This is what Windows Update, Mozilla Maintenance Service, Google Chrome Elevation Service, Adobe Acrobat Update Service and similar services do.
If you do not want to implement a service, but you want the application to be used by all users of the machine, you need to install it to a folder that can be accessed by all users, yet does not need Administrator privileges. You can for example use C:\Users\Public. See also Is there a shared folder in Windows to which non-elevated users have write access?. You can use PUBLIC environment variable to resolve that path.
If the application is to be used by one user only, then you are ok with using C:\Users\Username\AppData\Local – {userappdata} in Inno Setup.
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