Computer tweaking while playing a game

[Ls9L]

So i was just playing Call Of Duty Cold War and then this happend.... After a restart of my pc it stopped but does anyone know why this happend and how to prevent it from happening again 

 

https://www.youtube.com/watch?v=tiOSEk7Wgl4&feature=youtu.be

[bebejapes]

8 minutes ago, Ls9L said:

So i was just playing Call Of Duty Cold War and then this happend.... After a restart of my pc it stopped but does anyone know why this happend and how to prevent it from happening again 

 

https://www.youtube.com/watch?v=tiOSEk7Wgl4&feature=youtu.be

What is the in game resloution when its full screen and what is your desktop screen resolution?