You must disable the automatic client detection as part of the client deployment properties. From a server with the Citrix Web Interface Management console installed, perform the following steps:
If you don't want to disable automatic client detection for the default Citrix Web Interface,
          you can disable automatic client detection on an alternate Citrix Web Interface and use
          the -u option for the kiosk session.
            On the Windows Start menu, click All Programs >
            Citrix > Management Consoles > Citrix Web Interface
            Management.
          
            In the left pane of the Citrix Web Interface Management
            console, click XenApp Web Sites and
            select your XenDesktop site in the results pane.
          
            In the Action pane on the right, click Client
            Deployment.
          
            From the Manage Client Deployment window, click
            Properties.
          
            Under General, click Client Detection.
          
 Under Client Detection, deselect Perform client detection at
          logon, as shown below. 
            Click OK on the Properties window and
            click OK on the Manage Client Deployment
            window.
          
Exit the Citrix Web Interface Management console.