Article ID: 972093
You switch audio from the computer speaker to the headset on a computer that is running Windows XP. When you try to adjust the volume during a call in a Microsoft Office Communicator 2007 R2 conversation window, you receive the following error message:
Cannot adjust the speaker volume. Try adjusting the volume directly from your computer or speakers.
To resolve this issue, apply the following update:
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/969695/ )Description of the update for the Communicator 2007 R2: July 2009