Client issues.

So, I recently had my client updated to the 7.5 patch and after patching I tried going in to a game. Champion select and using the client UI was running smooth but then once the game started loading in my screen minimized and I got a bug that said,

League of Legends.exe - Application Error - stating, The Application was unable to start correctly (0xc0000005). Click OK to close the application.

So, naturally, I restarted my computer > updated anything that needed to be updated > ran as Admin and tried a custom game and had the same thing happened.

Then I uninstalled everything completely and I noticed my legacy client was gone, so after digging on the forms I found how to reinstall it with my other client but, I can only run it by. Opening my C drive > going into Riot Games > League of Legends and opening in Admin the LeagueClient.exe

I got about 5 games (with a leaver buster wait of about 20 minutes) in after reinstalling it and then updated for patch 7.6 and the same problem occurs. So anything I am doing wrong about trying to get my client to work?

I also got another leaver buster ban over this.