New Post: Simplified Bootstrapper & Managed UI

Thank you for sending the prompt reply! I tried this approach:

           project.Load += project_Load;
            var msiFile = Compiler.BuildMsi(project);

        static void project_Load(SetupEventArgs e)
        {
            Func<bool> checkSoftware = () => CustomActions.SoftwareInstalled(CustomActions.RemoteConnectorGuid);
            if (e.IsInstalling)
            {
                if (checkSoftware())
                {
                    e.Result = ActionResult.Success;
                    return;
                }
                var tempMsiFilePath = Path.ChangeExtension(Path.GetTempFileName(), ".msi");
                var msiFileId = "RemoteConnector.msi".Expand();
                e.Session.SaveBinary(msiFileId, tempMsiFilePath);
                Process.Start(tempMsiFilePath).WaitForExit();
                e.Result = checkSoftware() ? ActionResult.Success : ActionResult.Failure;
            }
        }

And the project_Load handler is raised after the progress dialog of main installer shows up and when remoteconnector.msi is called, windows spits the error:

Another Installation is in Progress you must complete the installation before continuing this one

which I guess fair enough.
Any ideas on how to fix it?