How to: Set the Current Session
You can open multiple performance sessions in the Performance Explorer, and can then select one of the visible performance sessions to be set as the current session.
Visual Studio Ultimate, Visual Studio Premium, Visual Studio Professional
After you set a session as the current session, clicking Launch on the Performance Explorer toolbar will start profiling the current session.
To set current performance session
In Performance Explorer, right-click the performance session, and then click Set as Current Session.
The session name appears in bold.