Launcher won't open Client

I have spent too much time trying to solve this issue. I open league of legends (as admin) and it brings up the logo and then a grey bar appears on the bottom of the logo, from there it is frozen forever until I open task manager and kill the process manually. I have tried every trick, including: Deleting varius files and folders like lollauncher/lolpatcher etc, running league as admin, disabling and deleting all firewall/security programs, uninstalling and reinstalling league, running ccleaner, turning down monitor resolution, holding numpad key when launching the client as admin, and other "fixes" that have not helped in the slightest.

From all of my research it seems as though Riot is being quiet about this issue and not attempting to resolve it. I would really enjoy being able to play the game again one day...

I am running Windows 8.1, and there have been no changes to the computer that indicate why LoL would just completely stop working.