I have a pilot farm of 2 Xenapp 6.5 Rollup 1. w2k8 R2 SP1 Got a lot of "down" sessions system "freezes" maybe for hours 100%CPU Log on to console, sometimes it takes 30 min to be able to log in (VMWAre 4.1 guest) Have see popups on console that it could not contact licence server - could be a red herring System (PID4) taking 50% CPU after freeze any suggestions on where to look? Plan on loading Xenapp 6.5 rollup 2 to start with. I have these to evaluate as well 2661332 You cannot reestablish a Remote Desktop Services session to a Windows Server 2008 R2-based server http://support.microsoft.com/kb/2661332/EN-US Also, I checked that these are not installed on the machine, please install the following hotfixes as they update all the components to their latest versions and we have seen similar cases in the past which were resolved after these hotfixes were installed. 2383928 Remote desktop sessions do not completely exit, and you cannot establish new remote desktop sessions to a computer that is running Windows Server 2008 R2 http://support.microsoft.com/default.aspx?scid=kb%3bEN-US%3b2383928 979530 A Windows Server 2008 R2-based Remote Desktop server denies some connection requests randomly under heavy logon or logoff conditions http://support.microsoft.com/default.aspx?scid=kb;EN-US;979530 2578159 The logon process stops responding in Windows Server 2008 R2 or in Windows 7 http://support.microsoft.com/default.aspx?scid=kb;EN-US;2578159 2465772 An application or service that uses Winsock API or Winsock Kernel API may randomly stop responding in Windows Server 2008 R2 or in Windows 7 http://support.microsoft.com/default.aspx?scid=kb;EN-US;2465772 2265716 A computer that is running Windows Server 2008 R2 or Windows 7 stops responding randomly http://support.microsoft.com/default.aspx?scid=kb;EN-US;2265716 975777 There is a delay when you shut down, restart, or log off a computer that is running Windows 7 or Windows Server 2008 R2 http://support.microsoft.com/default.aspx?scid=kb;EN-US;975777 2505348 High CPU usage or a lengthy startup process occurs during WMI repository verification when a large WMI repository exists in Windows 7 or in Windows Server 2008 R2 http://support.microsoft.com/default.aspx?scid=kb;EN-US;2505348