I recently encountered an issue with COM port mapping with XenDesktop 7.5. The functionality was deprecated in XenDesktop version 7. There was a private hotfix listed in the forums which I obtained, but determined it was not required IF you do the registry entries manually. The private fix was simply the Group Policy Extensions so you can see the settings in the policy editor. I opted to not use it so future upgrades of the GPO extension would be unaffected by the changes in that fix. I'm sure Citrix will eventually re-incorporate the changes in a standard release.

The applicable entries will need to be added to the following key:

HKLM\Software\Citrix\GroupPolicy\Defaults\Deprecat ed\
REG_DWORD


Registry value name Description
AllowComPortRedirection Allow (prohibit) COM port redirection
LimitComBw Bandwidth limit for COM port redirection channel
LimitComBWPercent Bandwidth limit for COM port redirection channel as percent of total session bandwidth
AllowLptPortRedirection Allow (prohibit) LPT port redirection
LimitLptBw Bandwidth limit for LPT port redirection channel
LimitLptBwPercent Bandwidth limit for LPT port redirection channel as percent of total session bandwidth
AutoConnectClientComPorts Automatically connect COM ports from the client
AutoConnectClientLptPorts Automatically connect LPT ports from the client


If you need to enable COM port redirection, create the REG_DWORD value "AllowComPortRedirection" and set it to 1. A reboot is required. Reboot the desktop and test COM/LPT port inside the ICA session.

This fix is applicable for: XenDesktop 7, 7.1, 7.5, and 7.6 VDAs running on Windows 7, and VDI-in-a-box. The fix is not required for VDAs with Server OS (Windows 2008 R2).