To update a computer from the evaluation version of Lync Server 2010 to the licensed version of the software:
Updating from the Evaluation Version of Microsoft Lync Server 2010

1.Log on to the computer as a local administrator.

2.Click Start, click All Programs, click Microsoft Lync Server 2010, and then click Lync Server Management Shell.

3.In the Lync Server Management Shell, type the following command and then press ENTER:

msiexec.exe /fvomus server.msi EVALTOFULL=1 /qb
Note that you might need to specify the full path to the file server.msi. This file can be found in the Setup folder of the Lync Server Volume media installation files.

4.After Setup finishes running, type the following from the command prompt and then press ENTER:

Enable-CsComputer
5.Repeat this procedure on any other Front End Server, Director, or Edge Server running an evaluation copy of Lync Server. This procedure should also be performed on any Branch Office Servers that were deployed by using the Lync Server media installation files.
If you are not sure if the evaluation version of Lync Server is running on a given computer you can verify that by running the following command from within the Lync Server Management Shell:
Get-CsServerVersion