We have a IS2010 InstallScript setup which has been having .NET Framework 2 as a pre-requisite for a number of years. We are upgrading our application to .NET 4 and we switched to that pre-requisite.
Now, if the setup is ran on a new machine everything works fine. However, if it is run on a pre-existing installation it won't run che pre-requisite check so it will upgrade the app but not install the .NET4.
On further checking we discovered that the same behaviour happens if we remove the .NET2 from old installation and then run Repair Mode: it will just ignore the fact that the pre-requisite is now missing.
Is there a way to have IS check the pre-requisites even in update/repair mode, maybe via InstallScript or by fiddling with the setup pre-requisite editor?
Answering my own question in case someone falls in the same trap in the future. IS2010 and previous versions had a bug which has been solved in subsequent releases. We upgraded to IS2014 and sure enough, update mode now will install the pre-requisite (a new version of the .NET framework included).