We are shipping a product which has a dependency on .Net 4.0. THis essentially means that Any one below XP SP3 will not be able to use our product. Our product also has a dependency on Windows Installer 3.1. Now does Windows Installer 3.1 ship by default on XP SP3 onwards. Is there a way the user can downgrade from Windows Installer 3.1 on XP SP3 and above.
The MSDN article Released Versions of Windows Installer states that XP SP3 comes with Windows Installer 3.1.4001.5512 by default, though of course it can be updated as well to a later release. I'm not sure downgrading is possible to do easily, if at all. I don't think you need bother that a normal end user would have somehow downgraded the Windows Installer version that their OS came with.