Please help me "Out Of Range" Error

When I get past champ select in loading screen all I can see is a black screen with the error "Out Of Range", I have read lots on changing resolution and stuff, but nothing is working. This is very annoying. I have uninstalled, and reinstalled. I am kind of new to PC (coming from a mac) so if you can tell me how to get around the the solution that would be helpful. Thanks!