How does the installer know what files to update?

ken rentz · Post by **ken rentz** » Tue Sep 05, 2006 6:49 pm

Should I change the revision code even when working on internal releases? I produced an updated release for testing and did not change this number. when run, this installer would not update the files from the earlier one.

MichaelNesmith · Post by **MichaelNesmith** » Tue Sep 05, 2006 8:24 pm

Yes, this is default Windows Installer behavior. Windows Installer won't even check to see if the MSI package is different if two packages have the same revision code. For these reasons, the IDE's default setting is to auto-update your revision code for you.

ken rentz · Post by **ken rentz** » Wed Sep 06, 2006 10:54 am

That explains things.

Is there a good reference describing the "under the hood" behavior of the windows installer side of things? Making a basic installer for our program was quite easy. The problems that I'm encountering have to do with updating older program installed with a non-msi installer. Patching up 4 existing versions of programs and maintaining user settings, data, etc. Trying to figure out what is happening with these various combinations is a bit of a challenge.

MichaelNesmith · Post by **MichaelNesmith** » Wed Sep 06, 2006 11:17 am

InstallAware protects you from most of the MSI internals. If you do want to read up on them

, you can study the Platform SDK Documentation. There is ample documentation there - but it will take a bit of research!

jimo · Post by **jimo** » Wed Sep 06, 2006 2:41 pm

Ken,

When we moved from a non MSI installer we found through trial and eror the best method was as follows:

1. Read in from the registry or ini files etc all user configuratino options
2. Invoke the current uninstall program
3. install your updated app

Then in the future applying patches and updates will be simple.

Hope this helps.

ken rentz · Post by **ken rentz** » Wed Sep 06, 2006 3:53 pm

jimo wrote:Ken,

When we moved from a non MSI installer we found through trial and eror the best method was as follows:

1. Read in from the registry or ini files etc all user configuratino options
2. Invoke the current uninstall program
3. install your updated app

Then in the future applying patches and updates will be simple.

Hope this helps.

The solution we’ve come up with that seems to work pretty good is to have a pre-install cleanup routine that only runs the first time the IA installer is used. It basically patches or uninstalls any troublesome components before the main install script starts installing things. This combined with forcing IA's installed features to match what an existing user has on their system seems to put things into a stable configuration. Unfortunately, since we are dealing with 3 versions of old releases, keeping user settings, data licenses, etc. is a real hassle.