The July 2008 Power Tools release for Team Foundation Server contains some really great additions to the product.  One of the more interesting features is the addition of a Team Members node to your team explorer.  This feature allows you to keep track of your team members, what they are doing and their presence information right inside Visual Studio.

However, that presence information comes from either Live Messenger or Office Communicator and in some cases if you aren’t logged into the client you will see an error.  To avoid that error, you can disable presence information in the Personal Settings dialog.

Select the Personal Settings… menu item from the context menu on the Team Members node

From the dialog click the “Change…” button in the collaboration group

And from the Choose a Collaboration Provider dialog you can select <None>

At that point you can OK your way out and you should be good to go.