My ios 8 update freezes and crashes to the main screen why?

My iOS 08 updates that I downloaded a few days ago freezes up and crashes each time I use it on the iPhone 4s that I have. I would liken I know how do I make it stop?

Try resetting your phone completely. Backup your phone first so you don't lose anything important you might want to keep on your phone. If that doesn't work then wait for a software update. Remember, this is the first version of iOS 8 out.