I ran across an issue with Service Pack 1 for Windows Server 2008 R2. In several cases once the service pack was installed I could not log on the servers remotely. Some research found that the issue was with update KB 2667402. On one server I was able to resolve the issue by checking for updates again. On another I had to uninstall KB2667402 and leave it uninstalled. I found the answer to this issue at http://social.technet.microsoft.com/Forums/en-US/winserverNIS/thread/f5d… Thanks to posts by MyITNetowrk and Gryffon-G-Wiz.