In case you didn’t gather it from the title, I need to point out that this is completely unsupported and generally not recommended. The Release Candidate version of Lync (and virtually every pre-release version of Microsoft software) is not intended to be upgraded to the RTM version through any method. It’s entirely likely that this breaks something and I simply haven’t encountered it yet. However, there are some people (like myself) who have many RC environments for testing, demos, etc. and would like to easily move those to RTM. Since you agreed in the licensing terms not to install RC in production we’ll assume you are only doing this on non-production systems and if this process completely blows them up then it’s really not a big deal. Disclaimers out of the way, I have done this 4 times now (3 times this morning alone) and it seems to work well for me. The best part is that it only takes about 15 minutes.
This is mainly to avoid a reboot. Stop all the Lync Services and the World Wide Web Publishing Service. I like using Get-Service -DisplayName Lync* | Stop-Service -force to stop the Lync services.
Uninstall the RC bits
The first step is to uninstall all the RC software. Don’t forget to uninstall UCMA also, which is a little lower down the list. You may have more items installed than I’m showing below depending on what roles you installed. You’ll want to uninstall Core Components last.
Most of the items you uninstall will return this error. Just click yes to keep going.
Run Setup from the RTM bits. Prepare AD should be marked as complete since the schema didn’t change from RC to RTM. Go ahead and install Topology Builder so we can upgrade the CMS database.
Enterprise Edition Only
Launch Topology Builder and, when it’s ready, download the existing topology. You will be prompted to save to a file, just enter any file name you wish.
Click Install Database…
Your database list will appear. Check the box next to the databases you want to upgrade and click next. You’ll notice on the next screen that a Minor Version Upgrade takes place.
Standard Edition Only
Click prepare Standard Edition Server. This will upgrade the CMS database that exists with your Standard Edition installation.
Installation and Certificates
Now you will just go on with the rest of the setup process. In the main setup window click Install or Update Lync Server System.
Next, run through each of the setup steps below.
When you get to the Certificate step you should be able to simply click Assign and reassign the certificate you were using previously.
Now just start the services and you’re good to go.