Open beta

I cant download league, it gives me an option to download the beta. I select yes, but then nothing happens to the client. I then click launch(this was available since the beginning).After I hit launch the client then closes and an error message pops up and says "League of legend has encountered a problem. Please install League alpha client to try again". The problem is that the option to get alpha client doesn't pop up again, I repeatedly uninstalled league and redownload but the same thing keeps happening. What do I do?