Does anyone know how to open games in a small window?

What game?

Some support windowed mode some don't.

Hi. I think most of the games to be opened in a small window, you have to go to the game exe file and then right click, properties, and look for the window where says run in: Full screen, Window, and some games have other options as well. But atention,this will not work with all the games,just with some. Hope this can help you.

Some do some don't. You'd have to run a virtual machine in windowed mode to be able to run all games windowed.

did you try alt-enter?