Microsoft Lync 2010 Group Chat and Microsoft Lync 2010 are both included with Microsoft Lync Server 2010. Because the two clients share several capabilities, it is helpful to know how the two interact. The behavior of the two clients depends on which one is designated as the preferred client.

For example, when Lync 2010 Group Chat is the preferred client, Contacts lists appear and can be updated within Group Chat. Lync 2010 also updates its Contacts lists with these updates. If Lync 2010 is the preferred client, Group Chat does not display the Contacts list and because it is not available, no instant messages or instant messaging (IM) conversations can be initiated through Group Chat's Contacts list. However, you can double-click participants in a chat room and initiate IM conversations by using Lync 2010.

In a scenario where Group Chat is not the primary IM client, there are two differences to note. First, a Contacts list which would appear in the My Chat panel if Group Chat were the primary IM client does not appear. Second, participants in the particular chat room that you are in still have presence information associated with them. You can still initiate IM conversations with them. To do this, double-click the participant's name, which opens a Lync 2010 Conversation window.