John Rice from our office just posted this on our internal blogs. He asked me to post it here as he has not yet set up his external blog. John has been setting up a new Lync server internally and he has had to work hard to find “correct” information about how to install Lync every step of the way. This post contains valuable information on what to do if you have to clean up your AD after removing an older OCS or Lync server installation in order to be able to add users to your new Lync install. This does not apply if you are migrating to a new Lync install from OCS or another Lync (implies OCS and or Lync servers are still functioning in the domain).
After you have removed an OCS Server or a Lync server from your Active Directory you will find that there are still various OCS or Lync Attributes defined on your user accounts
Using ADSI Edit open up the Default Naming Context and move down to the OU where your users accounts are contained.
Select a user and using the right mouse button choose properties. This will open the Attribute Editor
The following Attributes will need to be cleared from your users attributes:
msRTCSIP – DeploymentLocator
msRTCSIP – FederationEnabled
Once you have completed this task you have cleaned all the user attributes that reference the Old OCS or Lync Server. When you add users to the new Lync server these attributes will be repopulated with data specific to the new Lync installation.