The Virtual Desktop Agent has to be present on the virtual machines (VMs) to which your users will be connecting. It enables the machines to register with controllers and manages the HDX connection between the machines and the user devices.

If you are using XenDesktop or Provisioning services to provision VMs, you need to install and configure the Virtual Desktop Agent only once, but if you are using separate stand-alone virtual or physical machines you must install it on each of the machines so they can register with the controller to allow user connections.

You can install the Virtual Desktop Agent from a console session or from an RDP session, but installing from an ICA session is not supported.

To install the Virtual Desktop Agent, insert the XenDesktop installation media in the appropriate drive or mount the ISO in the appropriate virtual machine (VM). The following is a summary of the steps you are prompted to complete:

1. On the Installation page, select Install Virtual Desktop Agent.

2. On the next page, select Advanced Install unless you are setting up a proof of concept evaluation deployment, in which case you should select Quick Deploy; setting up an evaluation deployment is described in Evaluating XenDesktop 5. The rest of this procedure describes only the steps to follow when you are carrying out an advanced installation.

3. Select the components you want to install and where you want to install them. If you plan to deliver XenApp applications to your users, select Support for XenApp Application Delivery.

4. Specify the controllers in the XenDesktop site to which the Virtual Desktop Agent will connect, either by manually entering the locations or by selecting controllers from Active Directory. Alternatively, select Configure at a later time if you plan to specify controller locations later using Group Policy or by rerunning the Virtual Desktop Agent installer.

   Important: Ensure that you specify the locations of all the controllers in the site, otherwise some user connections may be refused. For load balancing, the Virtual Desktop Agent automatically distributes connections evenly across the controllers.

5. Configure the agent as follows:

   • Reconfigure the firewall. If the Windows firewall is detected, the necessary ports can be opened automatically for you. If another firewall is detected, you are told which ports you need to open manually for XenDesktop to operate successfully. You can also request to have the necessary ports opened for Windows Remote Assistance and Windows Remote Management.
   • If this installation is running in a VM on a hypervisor, you can select to have the VM automatically optimized for use with XenDesktop. Optimization involves actions such as disabling offline files, disabling background defragmentation, and reducing the event log size. For full information on the optimization tool, seehttp://support.citrix.com/article/ctx125874/ .

6. A summary of what is going to be installed appears.

7. When installation begins, progress is displayed on the screen.

8. When installation is complete the default is to restart the machine; you must do this for the changes to take effect.

You can also install the Virtual Desktop Agent through a command-line utility: XenDesktopVdaSetup.exe.

To deploy the Virtual Desktop Agent through Active Directory Group Policy, seehttp://support.citrix.com/article/ctx127301/.

Note: When you install the Virtual Desktop Agent, a new local user group for authorized RDP users is automatically created. The group is called Direct RDP Access Administrators. For further information on using protocols other than ICA, see http://support.citrix.com/article/ctx121657/.

XenDesktop requires desktops and controllers to have synchronized system clocks. This is required by the underlying Kerberos infrastructure that secures the communication between the machines. You can use normal Windows domain infrastructure to ensure that the system time on all machines is correctly synchronized.

To add or remove components, select the Windows option for adding or removing progams, then selectCitrix Virtual Desktop Agent. You can then select to add, remove, or reconfigure components, or to remove the Virtual Desktop Agent completely.

You cannot remove support for XenApp application delivery through the XenDesktop installation wizard; you must remove the plug-ins directly through the Windows removal option.

The Reconfigure Components option enables you to update the site and port numbers.