If you play games on your Windows 10 PC, you may have noticed the Game Bar pop up from time to time. This feature lets you record or stream games as you play them on your PC. If you don't use any of these features, you may wish to prevent the bar popping up every time you play games.
Do do this, click the Settings button on the start menu:
Then click Gaming:
Now disable the option labelled Record game clips, screenshots and broadcast using Game bar:
Next time you load a compatible game, the game bar will no longer appear. If you'd like to re-enable it, just toggle the option in the last step to "on".