The GeForce website now features a new beta version of the GeForce Experience which adds windowed capture modes, advanced microphone controls, and more. The summary recaps all that's new:

This month’s update continues to improve GeForce Experience, enabling you to record, broadcast, and take screenshots in fullscreen mode, windowed mode, or on your desktop even. Update to the new GeForce Experience Beta through the beta client, if you've installed a previous version, or download manually from GeForce.com. And learn more about the additional fixes, tweaks, and changes in this GeForce Experience beta release here.