Lync 2010 Cumulative Updates List

To ensure that you have the latest version of the Lync client, and the latest update, check out this frequently updated list of all client release versions for Microsoft Lync 2010.

Authors: Akshat Nigam, Microsoft senior Support Engineer and Thomas Binder, Microsoft UC Voice Architect

Editor: Susan S. Bradley

Publication date: March 26, 2013

Updated: April 21, 2014

Product version: Lync 2010

One of the most common checks that we do when troubleshooting Lync client issues is determining whether you are running the latest version of the Lync client and if all patches are installed.

A majority of the Lync client issues that get reported are resolved by upgrading to the latest release or update of the product. Thus, we highly recommended that you install the latest version of the Lync client, along with the latest updates, before you contact Microsoft Product Support. This article will help you identify the correct release version number.

To check the client version, from within the client, navigate to About Microsoft Lync, as shown in Figure 1 below.

Figure 1. Navigating to the About Microsoft Lync option

The version number in Lync 2010 is usually within the brackets on the second line, as shown in Figure 2 below (4.0.7577.4356).

Figure 2. Locating the Lync 2010 version number

Another way to check the client version is to look at the client UCCP log (communicator-uccapi-*.uccapilog) and look at any of the outgoing messages. For example, look at the initial REGISTER sent from the client, as follows:

03/19/2013|17:34:34.489 1EB4:1240 INFO :: REGISTER SIP/2.0

Via: SIP/2.0/TLS

Max-Forwards: 70

From: <>;tag=03a6c3d1d4;epid=7b6e0b7597

To: <>

Call-ID: 8a8324eeb0f84c9dbce136bb752e46f3


Contact: <sip:;transport=tls;ms-opaque=9359f8b23d>;methods="INVITE, MESSAGE, INFO, OPTIONS, BYE, CANCEL, NOTIFY, ACK, REFER, BENOTIFY";proxy=replace;+sip.instance="<urn:uuid:13DD5A72-ED31-5804-8CB4-861885BF1564>"

User-Agent: UCCAPI/4.0.7577.4356 OC/4.0.7577.4356 (Microsoft Lync 2010)

Supported: gruu-10, adhoclist, msrtc-event-categories

Supported: ms-forking

Supported: ms-cluster-failover

Supported: ms-userservices-state-notification

ms-keep-alive: UAC;hop-hop=yes

Event: registration

Content-Length: 0

Now that you have a number, how do you know which release is running on the client?

Each update (all Lync updates are cumulative updates) that is released by Microsoft for Lync has its own version number. You can determine the version number associated with an update by looking at the related KB article and noting the version of 'Lync.exe' in the File Information section, near the end of the article.

For quick reference, the following table lists the versions, release month, year, and a link to the KB article for all Lync 2010 updates released through March 2013.


Release Month, Year

Link to KB Article


RTM version



January, 2011


April, 2011


July, 2011


September, 2011


October, 2011


November, 2011


November, 2011


January, 2012


February, 2012


February, 2012


March, 2012


June, 2012


June, 2012


October, 2012


October, 2012


January, 2013


March, 2013


April, 2013


October, 2013

4.0.7577.4419 January, 2014


April, 2014


Additional Information

Lync Server Resources

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Keywords: Lync 2010, Lync 2010 Release Versions, Lync 2010 Cumulative Updates

Comments (6)
  1. Rodrigo Silva says:

    I am still getting the same problem when the version 7577.4445 is installed – Outlook Calendar does not sinc with MS Lync status, however it does not happen for a version 7577.4384 available for my Citrix Xenapp.
    I do not have the same version of my Xenapp available to install in my customer PC. In the last couple of months I have been tried to find it.
    Any idea??

    Thank you.

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