Question

We have an Excel AddIn say A written in C#, Add-In Express. The installer is built from setup project in VS.
Now we want to integrate it to another bigger add-in application say B.
we want to be able to uninstall A during installation of B.
B is also written in C#, but its installer is built from Advanced Installer.

I tried VBA like below, AddIns only contain “A XLL Add In” but not “A COM Add In”. so it does not work. So I am thinking to write an exe to detect if A is installed and if so, uninstall it.
and call the exe in installer of B.
Anyone know how to “uninstall a program in C#” ? or there is better solutions? thanks
Once I can detect A and uninstall it in an exe, I will be able to hook it in installer of B.
Installer/Uninstaller class in .NET is not an option since I am not using them in installer of B.

Dim item As AddIn
Set item = Application.AddIns("A COM Add In")

If Not item Is Nothing Then
    item.Installed = False
    'item = Nothing 'Not sure if this does anything
End If

    Dim item As AddIn
Set item = Application.AddIns("A XLL Add In")

If Not item Is Nothing Then
    item.Installed = False
    'item = Nothing 'Not sure if this does anything
End If

Answer 1

You can uninstall the previous version by invoking MSI directly:

msiexec /x YOUR-PRODUCT-CODE

Replace YOUR-PRODUCT-CODE with the real product ID used in your MSI package which installed the AddIn A.

You may want to add /qn option to completely suppress its UI.

MSI also provides API you can use to find out if the product is installed and to uninstall it.