League client crashes when trying to start game (please help)

I've tried a lot of things to fix it, i looked it up and found out it was a problem awhile ago about screen resolutions so like it said i looked at the game.cfg file, checked it had the right resolutions (it had) so i tried a full repair (didnt change anything) so i uninstalled and reinstalled league (didnt fix it), then i looked for the game.cfg file again but i dont have one now, so i tried making one and changing the window mode to 1 but that didnt fix it, not even sure if the game.cfg file is syncing properly with league as i had to copy it off the internet, previous versions i had deleted... please help as i am unable to play any league game as, it crashes whenever i start...