Re: Pixels flickering and then main menu freeze.
So, I honestly can't thank you enough because that worked.
I tried disabling HD4000 first and it fixed the rendering issues but the frame rate in-game was really low even with everything in low settings (when I got to play I could play everything in Max just fine and with HD texture mods). I then tried disabling Radeon 7600M and it seems like that fixed it because both games run smoothly (No BSOD from LoL and I let it run for some minutes in a costume game).
I don't know how to check which one it was using but it looks like it works just fine with the HD4000 by itself. I wouldn't want to sit with this fix in case it gives problems in a future, would it? And yes, I was grabbing the drivers directly from the official sites.