League won't open at all

So, today I was trying to open League, and then it said the client needed to update and had to be restarted. So I did and then the login screen came up. When I tried to login, it froze. So I exited out, and tried to get back in. But when I tried to open League up again, it showed the LOL logo for a brief second, then disappeared. I waited for the login screen to come up, but nothing showed up. I tried to keep opening up League, but nothing happens. And it still keeps going on. How can I get League open?