Ok, every time I try to log in I either get a Maestro error (There was an error connecting with Maestro.League of Legends will now exit. Please try restarting the application.), or a Connection Failure error both of which cause me to close my client.

My computer just had a system recovery on it so its pretty much factory defaults (I just got it back from HP after they fixed it) and my firewall is turned off. Also I was playing it before I had to send it into HP without problems.