Client not loading

There is this super annoying bug that keeps happening to me when I try to start a LoL game. Quite often, when I try to load in a game, the client takes forever to load, I usually have to restart it, and by the time it re-loads, the enemies are already level 4. This used to happen minimally, but it now starts happening more and more often, and its impossible to deal with. My entire team flames me for losing my lane, I can't earn any loot from the game, and the leavebuster puts me in a lower priority queue thinking that I deliberately went AFK. I don't really know what to do. I have tried un-installing and re-installing LoL, turning off the firewall of my computer, and closing all other programs, but nothing works. In case its helpful, I have a windows pc. Thanks, and let me know if you have any ideas.[sg-janna]