You’ve tried repeatedly to remove a screw, and now you've managed to strip the head. Don’t automatically reach for the drill! You could cause a lot of damage to your walls and end up with a gaping hole that you'll need to patch and repaint. Instead, place a large rubber band over the head, and insert a screwdriver over the rubber band and into the groove. Slowly and carefully turn the screwdriver until the screw is loose enough for you to remove it easily by hand.