League client not Launching

When i click on the LoL icon to open the game it just pops the league symbol with a little loading bar under it onto my screen for a moment, then it dissappears and nothing else happens. I cant even get to the patcher let alone the actual client. Ive tried uninstalling/reninstalling, restarting my computer and running as admin plus a few other suggestions i found on the boards but nothing is working. If anyone can make a suggestion id love the help :/