Lync Server CU5 (February 2012) Released

A quick post in case you missed it, the Lync 2010 server Cumulative Update 5 (CU5) has been released. This update includes client (include mobile) updates as well as server updates.


March 19, 2012 Update: The CU5 update for the Lync for iPhone and Lync for iPad apps have been released on the Apple Store.

This iOS update enables the Lync clients to sign-in using Forefront UAG 2010 SP1 as a Reverse Proxy.


This includes fixes for most major Lync server 2010 roles including the administrative tools, the core components, and the mobility service.

As usual the cumulative installer is available in the LyncServerUpdateInstaller.exe download.


The associated CU5 Lync Client updates are also available:

A Good Overview of all the CU5 Updates

Client Notes

  • One the several Lync client CU5 updates fixes is the F1 help issue (introduced in the CU4 update).
  • This update brings the client version up to 4.0.7577.4072.

The update will need to close Outlook and it will prompt to do so:

7 comments to Lync February 2012 Updates are Available

  • Jim

    Oh, that page talks about the client install. I was referring to just the CU5 on a system that already has Lync installed.

    • You can deploy CU5 (or any Lync client update) silently using the Lync client Windows Installer patch (.msp file) and msieexec.exe as follows:

      > “msieexec.exe /patch lync.msp /quiet”

      However, even in silent mode, it will close Outlook, install CU5, and re-start Outlook.


  • Jim

    So it’ll close Outlook when installing CU5 silently, but then re-open it after the update completes?

  • Jim

    Is it possible to use the “Do not close applications. A reboot will be required.” option when doing a command line silent install (like remotely via SCCM for example)? What would be the parameters to do so? We’d like to push out CU’s as they’re released, but users have a habit of leaving Outlook open which can be problematic, especially if they’re in the middle of something. It would be far better to at least get it installed and then just wait for the next client reboot.


    • Hi Jim,

      There is no option I am aware of for the Lync installer to “not close applications” and to suppress a reboot if required. You can see all of the Lync installer options here: (near the bottom in the “Lync 2010 Setup Command-Line Arguments”).

      Those applications (Outlook and Lync) typically need to close to install the hotfixes in the update. In my experience, this round of updates (CU5) do require the applications to close (the installer should be auto-restart the applications after the update has been installed).


  • Mur

    I find Lync is awkward to deploy. My users keep their computers running 24/7 and rebooting is generally very bad. All my deployment is behind the scene and I find Lync does not restart after it is updated.

    I would like any suggestions on how to deploy it silently so it starts Lync after installing, does not reboot the computer and does not force outlook to close.

    • I personally have found the Lync client more flexible to deploy than the previous Communicator client, and although not perfect, it goes fairly smooth depending on your deployment method.

      Lync will restart automatically after it is installed, so I am not sure what the problem is there. I have not had to reboot after installing Lync and after most Lync client updates either – unless they were part of other windows updates that did require a reboot.

      You can install it quietly with the latest patch by using this command “msieexec.exe /patch lync.msp /quiet” (assuming the Lync.msp contains the patches install of the Lync client).

      Outlook will need to be closed to install the Lync Online Outlook Add-In, and the initial install of the Lync client will close Outlook for the user and restart it.

      I just sat through a Lync client deployment using a centrally deployed batch file and the command above. The Lync client and Outlook were restarted automatically and no reboot was necessary. FYI – this was a Windows 7 desktop.

      Take a look at my blog post Top 10 Facts when Planning a Lync 2010 Client Deployment ( and the comments for some issues if you are deploying with SCCM or a GPO.

      Hope that helps,

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