Various errors installing Lync. Lots of problems publishing the topology and kept getting an error message saying machine needed a restart. Tracked this to a GPO installing a printer for the user which generated a restart request (thanks HP!). Logged onto the server using a different account without this GPO and the installation ran as it should.
Installing a fresh Lync Server into a new domain. After finally installing the server (check sysprep! the orignal sysprep did not change the SID causing lots of issues) we could not enable any users. It came down to the fact OCS 2007 R2 was already installed and the user had a sip addresses assigned.
Solution: Remove the user from OCS which allows Lync to enable.