Citrix has been a major player in cloud computing, particularly known for their XenApp presentation product. XenApp allows hosting programs on a server for remote or local users to run them, similar to Microsoft Terminal Services but with the ability to publish single applications rather than full desktops. This capability is valuable in enterprise environments and educational institutions for publishing software like Microsoft Office.

Legacy Compatibility Challenges

Older programs based on the legacy Metaframe product often use specific methods for licensing or station identification. For example, some applications use the “Client Name” to handle licensing, which is forwarded into the Citrix session as the computer name.

Until Citrix XenApp Online Plugin 12.x, you could specify the Client Name. This was useful when customer computers weren’t named to match your application’s expectations. However, XenApp Online Plugin, Program Neighborhood, and similar products have been discontinued in favor of the new Citrix Receiver.

Citrix Receiver Overview

Citrix Receiver offers a simple and intuitive interface but lacks many settings in the base program. However, you can modify most settings through registry edits.

Warning: Registry editing should only be performed by experienced users. Always make backups and proceed with caution.

Key Registry Settings

TWIMode (Seamless Window Mode)

This setting controls whether applications run in Seamless Window mode. For users with high-resolution monitors, disabling seamless window mode might be necessary if the System Administrator hasn’t increased video memory for sessions.

Registry Keys (Windows User Level):

  • x86: HKEY_CURRENT_USER\Software\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Virtual Channels\Seamless Windows
  • x64: HKEY_CURRENT_USER\Software\Wow6432Node\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Virtual Channels\Seamless Windows

Configuration:

  • Find the “TWIMode” key
  • Default value is *
  • Set to 0 to disable seamless window mode
  • After disabling, set desired resolution:
    • DesiredHRES (horizontal resolution)
    • DesiredVRES (vertical resolution)
  • Common resolutions: 1024x768 or 1280x1024
  • Use * to disable resolution settings

ClientName

This setting forwards a specific computer name to applications, useful for legacy applications requiring specific computer names.

Registry Keys (Windows User Level):

  • x86: HKEY_CURRENT_USER\Software\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Client Engine
  • x64: HKEY_CURRENT_USER\Software\Wow6432Node\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Client Engine

Configuration:

  • Find the “ClientName” key
  • Default value is empty ("")
  • Set to desired computer name
  • Empty value enables Dynamic Client Name mode (forwards actual computer name)
  • Changes require session restart to take effect

Best Practices

  • Test all registry changes thoroughly before deployment
  • Document any custom settings
  • Create backup of registry before making changes
  • Consider creating a script for consistent deployment
  • Monitor application behavior after changes

Conclusion

While Citrix Receiver offers fewer built-in settings than its predecessors, most functionality can be restored through registry modifications. The key is to understand your specific requirements and make targeted changes to support your environment’s needs.

Remember that registry editing should be approached with caution and proper testing. Always verify changes in a test environment before deploying to production systems.