They disable the windmills by rotating the blades so it is parallel to the wind flow so the wind goes through it without rotating the turbine. If you look at windmills that aren't moving, you'll see that the blades look thinner than the ones that are, because of the rotation.,(reply>), Oh neat! I was imagining they just locked it up and thinking that sounds <b>more</b> likely to be damaged by wind.,(reply>), It's called feathering the blades. But yes you're correct.,(reply>), One more note, this is the preferred method of stopping a turbine because if you applied breaks like he said you'd end up with massive wind loads on the blades. By rotating you also reduce (but certainly not eliminate) the wind load along the blade.