Hi, I have a question regarding "Features/Always Install". I am uncertain if this title means "ALWAYS install".
At the moment this is populated with various dll's (all Microsoft) which were automatically imported from a VB project. What I really want is these to only be installed if they are more recent than any existing version on the users computer. Is there a way to do this?
It's just a name, but typically this feature is not shown to the end-user, so there is no chance for it to be unselected manually. You can write system searches, feature conditions, custom actions, etc., each of which influence this feature's likelihood to install in other ways.
Sorry, I'm very new to this! I think you are saying that the "always install" only means that the end-user has no option to deny installation of these files which is fine.
I'm still unsure what happens if any of the files is already installed on their system, or if a more recent version is already installed. I do understand the standard MSI "file overwrite" rules but have no idea if these apply to these files.
I don't really understand your 2nd sentence, is there an example anywhere explaining- how to "influence this feature's likelihood to install"?
Windows Installer's file versioning rules apply to all files it installs as part of a feature>component>file relationship. (Other rules apply to DuplicateFile and such tables.)
As far as influencing a feature's likelihood to install, there are a multitude of approaches here. There are installlevels and feature conditions. There's the feature selection tree and control events such as AddLocal. There's properties including ADDLOCAL, and API calls such as MsiSetFeatureState. That's why I said influence - there's an ordering to how these are evaluated, and any later one can reverse the decision of an earlier one.
