Depending on the type of keyboard you got, like my Logitech keyboard has a "Gaming Mode" were it disables the windows key. Just look up your keyboard and type in how to disable windows key or turn on gaming mode.
My, Gaming Mode key is in the top left hand corner and it looks like a joystick and I just click it to turn on/off.
I highly suggest you use this technique in-game. Whilst mid-game you feel this thing you feel like your lagging. Simple fix!
Press ESC
Press down Alt+F4
And you should see a noticeable difference! Give this comment a like if it worked!