This article explains a new way to disable the Citrix ICA virtual channels.
In previous versions of the Windows operating system and XenApp when you wanted to see if a particular Citrix ICA virtual channel was causing performance issues you had to disable them for all users directly from the ICA-TCP port.

Starting with Windows 2008 and XenApp 6.0 these settings are no longer enforced if changed directly on the ICA-TCP these settings and many more have been moved to XenApps User policy subsystem.

This is a much better way of handling these settings as you can now test turning off the ICA virtual channels for just 1 user rather than disabling them for all users which could impact new connections while you are testing.

Note: This was and still is a very common troubleshooting step to help determine and narrow down a Citrix ICA Virtual channel that may be causing some minor performance issues for users.

Instructions

1. Open the Citrix AppCenter Console or the Citrix Delivery Services Console and go to the Policies node > User Tab.

2. Create a New policy you can name it anything you like my example is DisableVirtualChannels.
   

3. Once the policy is created, Disable or Prohibit the following settings (17 in total):

• ICA > Client clipboard redirection > (Set to Prohibited)
• Audio > Audio Plug N Play > (Set to Prohibited)
• Audio > Client Audio Redirection > (Set to Prohibited)
• File Redirection > Auto connect client drives  > (Set to Disabled)
• File Redirection > Client drive redirection  > (Set to Prohibited)
• Port Redirection > Auto connect client COM ports > (Set to Disabled)
• Port Redirection > Auto connect client LPT ports  > (Set to Disabled)
• Port Redirection > Client com port redirection > (Set to Prohibited)
• Port Redirection > Client com LPT port redirection > (Set to Prohibited)
• Printing > Client printer redirection > (Set to Prohibited)
• Printing > Client Printers > Auto-create client printers > ( Set to Do not auto-create client printers)
• Printing > Client Printers > Direct connections to print servers > ( Set to Disabled)
• Time Zone Control > Estimate local time for legacy clients > (Set to Disabled)
• TWAIN Devices > Client TWAIN device redirection > (Set to Prohibited)
• USB Devices > Client USB device redirection > (Set to Prohibited)
• USB Devices > Client USB plug and play device redirection > (set to prohibited)
• Server Session Settings > Single Sign-On > (Set to Disabled)

Note: The Single Sign-On setting just disables the use of the Citrix Password Manager Agent NOT pass-through authentication for the user.

4. Finish the Policy creation by applying it to a filter. (It is recommended to use the Client name or User filter since we want to turn off these settings for 1 user.)

5. If all the settings have been correctly Disabled or Prohibited you can see Configured settings equals 17 also ensure the box that says Enable this policy is checked then hit the Create button to complete the policy.
   

6. Before testing, move the policy using the consoles Higher button so that it is Priority 1 and also ensure Enabled shows the True value.
   

7. Now test the policy using the user it was applied to.