In default the Bkack Drop Down is not enabled, in webinterface.
To enable it, do this:
- On the Delivery Services server, navigate to: C:\inetpub\wwwroot\Citrix.
- Open the folder that represents the desired Store (example: Store1).
- With Notepad, open webinterface.conf.
- Search for the showDesktopViewer attribute.
- Change the attribute value from off to on.