You don't need to uninstall/reinstall League of Legends, go to programs and features and look for Pando Media Booster and uninstall it.
When you install LoL, it will silently install PMB. So if you ever reinstall in the future, check for it in your programs and uninstall PMB.
The two links I posted have tons of information.
Note: Really, Pando Media Booster just sounds like malware. installs without you knowing and steals your bandwidth and makes your computer download, maintain and send files without your knowledge.
That's pretty shady...
from your screenshot, PMB has 10x more bandwidth usage at 35Mb/s than your next highest program Chrome at 3Mb/s.....