On new Windows Vista / Window 7 computers remote desktop connections to a terminal server are slow
WARNING: The following information is provided “as is” as this is not really an issue related to Design Manager, but is an issue related to Microsoft Remote Desktop Services and Windows Terminal Server and therefore, is outside the scope of normal DM technical support. Design Manager makes no guarantees about the accuracy of this article and the information within should be used at your own risk!
Read the article here.