Question

I have made an application (in Visual Studio 2008). The installer for the first version was MSI based (that is, a deployment project). But for the second version of the application, I have decided that ClickOnce better suits my needs.

Can I make the installer the newer version (ClickOnce based) to uninstall the previous version (MSI based)? If yes, how?

Answer 1

There is no mechanism for this provided. You may be able to do it with a FullTrust ClickOnce application, then run msiexec /x <product guid>, and also make sure to invoke it with a runas verb so that it prompts for UAC elevation. Something like…

var options = new ProcessStartInfo
    {
        Verb = "runas", //Needed in Vista and Windows 7 for UAC
        Arguments = "/qn /x <your product guid>", //qn = quiet with no UI
        FileName = "msiexec"
    };
Process.Start(options);