What the hell causes my games to exit to desktop? And defocus apps?

I'm on hp pavilion g7 laptop pc windows 8

when i'm playing gta 4 or minecraft evry five seconds it takes me to desktop
when i'm typing it stops like if i pressed on the taskbar
i already scanned it for virus & malware and nothing

Its an issue with your video car. Uninstall the drivers and reinstall, if that dosn't work try changing the settings your games are running on