Do I need .NET framework for LoL? Because I'm trying to stop the lag and I'm wanting to uninstall .NET but I'm afraid it will ruin everything so I'm asking ya'll first.

A lot of software and games use the .net framework to run. Do not uninstall it. You'll probably cripple another program or programs.

LoL doesn't need anything except a 3D video card to run.

.net isn't causing your problem and you will end up having to reinstall it once you realize how many other things you destroyed by uninstalling it ;}