A: Citrix XenDesktop supports deployments to Active Directory (AD) environments where user and computer accounts exist in a single AD forest (at all forest and domain functional levels). XenDesktop can also support deployments to AD environments where user accounts are in different forests from the computer accounts of XenDesktop controllers and all virtual desktops. For this second situation, the domain or domains containing the XenDesktop controller and all virtual desktops must trust the domain or domains containing the user accounts. This trust can be a forest trust or an external trust. The situation where XenDesktop controllers and virtual desktops are in separate forests is also supported (at all forest functional levels, and at domain functional levels above Windows 2000 Native) when a bi-directional trust exists between the two domains.