Article ID: 2501647
When Lync Web App opens inadvertantly, using the x64 version of IE while joining a Lync Server 2010 meeting the following informational message is presented:
The web browser is not supported
Microsoft Lync Web App cannot open in this web browser.
The x64 version of Internet Explorer (IE) is open when the meeting participant clicks on the meeting's email Invite "Join online meeting" link to join a Lync Server 2010 meeting using the Lync Web App client. By design the Lync Web App client cannot be launched in a 64 bit browser
IE is installed on all x64 Windows server and client operating systems with a x64 version and a x86 version of the browser. This design feature provides support for all 64 bit and 32 bit browser based applications. To use Lync Web App with IE installed on a x64 Windows operating system:
Lync Web App Supported Platforms
(http://go.microsoft.com/fwlink/?LinkId=151500)for other considerations.