Windows 7: When Im Playing Any of my games they will just exit out of full screen

When playing any games like planetside 2 or tf2 anything on full screen. It will just got to the desktop. So then I would have to go click on the game to open it back up to play and then a minute later it will do it again. Is there any way to fix this because I have become frustrated with this occuring repeatedly. If someone could post how to fix this that would be awesome. Thanks.

I'm having the exact same problem

Anyone have a fix?

It happens 2 me also when playing 2K games ; which have been modified from original DOS games; Win 7 doesn't like DosShell. It will knock the game down 2 bottom strip; when u click it comes back in small screen; SAVE then restart a load 2 resume . On my sys - what causes it is NativeHost.exe & if u have ur computer set 2 automatic updates of Win; any update 2 .FramesWork Net . I had 2 reset updates 2 start at a certain time; because if u set u notify , it interfers w/game.

So basically just turn off automatic updates?

anyone else have any ideas?