VS2008 Setup Project: Uninstalling the previous MSI

Question

I have a VS2008 setup project, which creates a setup.msi which installs a WinForms application (C#).

Every time I update the version number, the users first have to unin

Answer 1

Semi-answering my own question, just for the benefit of anyone who's interested:

Firstly, I found an incredibly useful article on how MSI updates work.

Secondly, I found InstEd, a rather nice freeware MSI editor, which showed me that there was nothing obviously wrong with my MSI file. (Yes, I could use Orca instead, if I didn't mind downloading the whole Windows SDK to get it.)

Thirdly, and annoyingly, the original problem seems to have fixed itself and I can't reproduce it any more. If it comes back, and if I fix it again, I'll add a comment here!

Anyway, all this brought up a new - arguably worse - problem: the MSI now claimed to update the application but didn't actually install anything! The solution to that is as follows:

• AssemblyVersion doesn't matter, but AssemblyFileVersion absolutely does: it must increment, if you want the new files to be installed. (This is a change in VS2008, compared to VS2005. See, for instance, this discussion on the Microsoft groups.)
• However, AssemblyFileVersion can't autoincrement the way AssemblyVersion can. Setting it to 1.9.* (or whatever) will just result in an error. The solution, from Stack Overflow this time, is to set AssemblyVersion to autoincrement, and then open AssemblyInfo.cs and remove the AssemblyFileVersion attribute altogether. This will force the file version to equal the assembly version.