How to i make my Cod BO windowed?

as title says, how to i make my CoD BO Windowed via steam?

Start the game. SP or MP.

Go in Options.
Screen/Display (I don't remember but with the screen)
And there you will find: Window Mode / Full Screen Mode. ( I don't remember here either. But I think its the 2 or 3th option.)

Or just watch this shit:

or you can just enter the following commands into your console:
Firstly enter "/r_fullscreen 0"
And then "/vid_restart"
If you want to get your BO back to fullscreen, type in "/r_fullscreen 1", and then again "/vid_restart".

Hope it helped