Ah, you're looking to EXTRACT hair from an image. Although there are some fancy filters out there, the most reliable method for such an organic and wispy object is the Photoshop quickmask feature. Simply hit Q on your keyboard and start painting over the hair. If you have a pen tablet set the brush size to be variable by pen pressure and the opacity to be consistent. Without a pen tablet expect the task to be quiet tedious, but still doable.