If the hairpieces are conforming items, they must be conformed to the intended model.  If they are props, then they must be parented to the intended models.  We need more information about the content you are attempting to use so we may give accurate advice on how to proceed.  What type of hair are you using and to what model it belongs?  

Judging from the image, you may have parented a hairpiece to the forearm.  Also, you have too many lights in your scene, that will slow down your software.