The application and the controls are 32bit and must be accommodated as such in the Citrix environment. For the same reason, all utilities and even the CMD prompt should be run “As Administrator” to insure the correct 32bit updates are made in the registry.
Running 11.5 CA Web Viewer on a Citrix Server - 64 bit (IE7) and cannot register ActiveX controls - Printx.ocx and Mapimail.ocx. Why can’t users can't print or email?
Windows 2008/2012 Server
Put the ActiveX controls in a shared folder on the Citrix server that is authorized for "Everyone", or at least IWAM and IUSR, and register the controls in that folder. Copying the OCX files into the Windows\system32 folder for example, logging in as local admin on the server and registering them should allow end-users to open the OMWV webpage so that the OCX files are installed again. Then the users should be able to print and email without difficulty.
Important Additional Information:
This article contains information about modifying the registry. Before you modify the registry, make sure to create back up of the registry and ensure that you understand how to restore the registry if a problem may occur. For more information about how to back up, restore, and edit the registry, please review the relevant Microsoft Knowledge Base articles on support.microsoft.com.