Settings Messed Up

Backstory: My computer broke a few months ago. No problem I have been playing on either of my brothers depending on whos is free. The settings have been fine up until now, changing back to mine when logged onto my LoL account. But a couple of days ago when i played on my brothers pc it was on his settings despite being on my account. It made me play significantly worse and I can no longer play on the settings that I find most comfortable.