How to use Windows 10's game DVR tool to capture video in any app
The new feature only works in more recent updates to the Windows 10 insider preview. Don't expect to see the Game bar option if you're on the slow update ring running the now ancient Build 10074 or something similar.
We should also point out that it's not yet clear if this feature will function the same way in the final version of Windows 10 that begins rolling out on July 29. Considering how close we are to the official launch date, however, it's a good bet this feature will last.
Now let's get to the good stuff.
You can call up the Game bar by hitting the Windows logo key + G. However, you can't call it up anywhere. In our tests, for example, you wouldn't see it on the bare desktop, File explorer, or Notepad. Try it out in anything else--such as a modern UI app or the Steam dashboard--and it should work. In other words, this feature appears to be limited to apps and won't work for system level activities.
Once you hit the Game bar shortcut, a pop-up window will appear as seen above that says Do you want to open Game bar The only option is a checkbox that says Yes, this is a game.
Click that checkbox and the Game bar will appear. Now you can just hit the red record button to start your recording session, or you can use the keyboard shortcut Windows key + Alt + R.
That's about all there is to this feature. You can find your saved videos in the Game DVR section of the Xbox app, or inside your user folder under Video > Captures.
The impact on you at home: We should note that we tested the Game bar in a virtual environment for the Mail screenshots. While we were able to get the Game bar to appear, we did not have the option to record anything because the virtual machine's hardware settings weren't robust enough. Regardless, if you have Windows 10 running on bare hardware this trick should work for you, which we verified by testing the Game bar with HipChat on a machine with Windows 10 installed on the hard drive itself..