Game still freezing pls help

at the start of every game for some reason it will freeze completely forcing me to have to shut down my computer and have to restart in order to get in it happens about 50% of the time and is getting really annoying have posted a forum of this before but it got taken down or something really don't know if someone knows how to fix this issue pls help me or if riot could contact me in some way to fix this issue thank you very much