Hi Paul,

In your scenario, I would suggest to check (from your Web Installer) the
currently installed version or build.

Let us assume your customer is on Version 1.6. You sent links to 1.7 and
later 1.8 but they "forgot" to install it. Now you send out Version 1.9.
Let the Web Installer check the required previous version (e.g. Version 1.8)
and you are done. If the customer is not on a valid previous version,
display an error message and ask him to apply the previous version(s).

Or develop the setup.exe in such a way that it can automatically handle it.
For example, our own SetupBuilder 10 installer and web update can bring any
previous SetupBuilder 10 to the latest build.

Friedrich