I was trying to add a Virtual Server 2005 host to a Virtual Machine Manager 2008 Beta and I kept receiving the following error:
Agent installation failed on MBC02.mbccs.internal because of a WS-Management configuration error.
See the Virtual Machine Manager Help for information about configuring WS-Management.
Of course, being a beta product, that help section didn't exist and a search for "WS-Management" didn't yield anything. WS-Management is installed by adding "Hardware Management" from Windows Components > Management and Monitoring tools (WinRM service), and this was installed on my server so I was pretty confused as to why I was receiving this message.
It turns out that you need to install WS-Management v1.1 which is provided as a hotfix from Microsoft. You can download it from http://www.microsoft.com/downloads/details.aspx?FamilyID=845289ca-16cc-4c73-8934-dd46b5ed1d33&displaylang=en.
Hope this helps!