Note: This is the opposite procedure to CTX137209 - How to Change VDA Display Adapters from XP Display Driver Model (XPDM) to Windows Display Driver Model (WDDM). Display Mirror Driver under Display Adapters, as displayed in the following screen shot: If you are using WDDM drivers, the Device Manager shows Citrix Display Driver ( Citrix Systems – WDDM and Citrix Systems Inc. For testing purposes, occasionally Citrix Technical Support Engineers might request you to change the display adapters within the VDA to use the older XPDM drivers instead of the newer WDDM drivers. Backgroundīeginning with version 5.5 of the XenDesktop VDA software, the legacy XPDM display drivers (pre-Vista) were updated to WDDM (post-Vista) drivers. This article describes how to change Virtual Desktop Agent (VDA) display adapters from WDDM to XPDM drivers.