Uninstall an application programmatically

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.

Answer 2

You can use the same Upgrade Code for both installers. If Upgrade Code is the same and installer B has a higher version than A, then A package will be uninstalled by MSI during the installation of B.

Answer 3

Your approach is correct - in particular the exe you are creating should be Setup.exe which will ensure that the pre-requisites are met. Ie it will uninstall A.

How you create setup.exe is very dependent on what tools you have to hand though - sorry I can help you much there as I use wix3.0 which is quite limited in this particular regard.

Answer 4

You can use WMI - ManagementObject to accomplish this.

 ManagementObjectSearcher search = new ManagementObjectSearcher("SELECT * FROM    Win32_Product"); 

 ManagementObject product = search.Get().Cast<ManagementObject>().ToList().Where(obj
=> obj["Name"].ToString().StartsWith([Name of product to Uninstall])).FirstOrDefault();

 if (uninstallObject != null)
    object result = product.InvokeMethod("Uninstall", null);