Client Crashing Once I click LAUNCH

I've been having problems with my client every since 6.2 came out. It would crash after champ select so I even tried reinstalling. League wouldnt uninstall so I had to restore my laptop to factory settings. I just reinstalled league and now I cant even log in. Once I click LAUNCH, the entire client and window closes. Im not sure what to do anymore, i've tried everything. HELP PLEASE!!!