InPlaceHostingManager iphm = null;

public void InstallApplication(string deployManifestUriStr)
{
    try
    {
        Uri deploymentUri = new Uri(deployManifestUriStr);
        iphm = new InPlaceHostingManager(deploymentUri, false);
    }
    catch (UriFormatException uriEx)
    {
        MessageBox.Show("Cannot install the application: " + 
            "The deployment manifest URL supplied is not a valid URL. " +
            "Error: " + uriEx.Message);
        return;
    }
    catch (PlatformNotSupportedException platformEx)
    {
        MessageBox.Show("Cannot install the application: " + 
            "This program requires Windows XP or higher. " +
            "Error: " + platformEx.Message);
        return;
    }
    catch (ArgumentException argumentEx)
    {
        MessageBox.Show("Cannot install the application: " + 
            "The deployment manifest URL supplied is not a valid URL. " +
            "Error: " + argumentEx.Message);
        return;
    }

    iphm.GetManifestCompleted += new EventHandler<GetManifestCompletedEventArgs>(iphm_GetManifestCompleted);
    iphm.GetManifestAsync();
}

void iphm_GetManifestCompleted(object sender, GetManifestCompletedEventArgs e)
{
    // Check for an error.
    if (e.Error != null)
    {
        // Cancel download and install.
        MessageBox.Show("Could not download manifest. Error: " + e.Error.Message);
        return;
    }

    // bool isFullTrust = CheckForFullTrust(e.ApplicationManifest);

    // Verify this application can be installed.
    try
    {
        // the true parameter allows InPlaceHostingManager
        // to grant the permissions requested in the applicaiton manifest.
        iphm.AssertApplicationRequirements(true) ; 
    }
    catch (Exception ex)
    {
        MessageBox.Show("An error occurred while verifying the application. " +
            "Error: " + ex.Message);
        return;
    }

    // Use the information from GetManifestCompleted() to confirm 
    // that the user wants to proceed.
    string appInfo = "Application Name: " + e.ProductName;
    appInfo += "\nVersion: " + e.Version;
    appInfo += "\nSupport/Help Requests: " + (e.SupportUri != null ?
        e.SupportUri.ToString() : "N/A");
    appInfo += "\n\nConfirmed that this application can run with its requested permissions.";
    // if (isFullTrust)
    // appInfo += "\n\nThis application requires full trust in order to run.";
    appInfo += "\n\nProceed with installation?";

    DialogResult dr = MessageBox.Show(appInfo, "Confirm Application Install",
        MessageBoxButtons.OKCancel, MessageBoxIcon.Question);
    if (dr != System.Windows.Forms.DialogResult.OK)
    {
        return;
    }

    // Download the deployment manifest. 
    iphm.DownloadProgressChanged += new EventHandler<DownloadProgressChangedEventArgs>(iphm_DownloadProgressChanged);
    iphm.DownloadApplicationCompleted += new EventHandler<DownloadApplicationCompletedEventArgs>(iphm_DownloadApplicationCompleted);

    try
    {
        // Usually this shouldn't throw an exception unless AssertApplicationRequirements() failed, 
        // or you did not call that method before calling this one.
        iphm.DownloadApplicationAsync();
    }
    catch (Exception downloadEx)
    {
        MessageBox.Show("Cannot initiate download of application. Error: " +
            downloadEx.Message);
        return;
    }
}

/*
private bool CheckForFullTrust(XmlReader appManifest)
{
    if (appManifest == null)
    {
        throw (new ArgumentNullException("appManifest cannot be null."));
    }

    XAttribute xaUnrestricted =
        XDocument.Load(appManifest)
            .Element("{urn:schemas-microsoft-com:asm.v1}assembly")
            .Element("{urn:schemas-microsoft-com:asm.v2}trustInfo")
            .Element("{urn:schemas-microsoft-com:asm.v2}security")
            .Element("{urn:schemas-microsoft-com:asm.v2}applicationRequestMinimum")
            .Element("{urn:schemas-microsoft-com:asm.v2}PermissionSet")
            .Attribute("Unrestricted"); // Attributes never have a namespace

    if (xaUnrestricted != null)
        if (xaUnrestricted.Value == "true")
            return true;

    return false;
}
*/

void iphm_DownloadApplicationCompleted(object sender, DownloadApplicationCompletedEventArgs e)
{
    // Check for an error.
    if (e.Error != null)
    {
        // Cancel download and install.
        MessageBox.Show("Could not download and install application. Error: " + e.Error.Message);
        return;
    }

    // Inform the user that their application is ready for use. 
    MessageBox.Show("Application installed! You may now run it from the Start menu.");
}

void iphm_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
    // you can show percentage of task completed using e.ProgressPercentage
}