League of Legends requires administrative privileges to install and run correctly. There are several fixes for this problem which are described below.
Check your Hard Drive for errors
Occasionally, these problems can be caused by a corrupt disk fragment. To check for corruption, run a Scandisk on the drive:
Reinstalling the game as an Administrator:
If all else fails you may need to re-install the game with administrative rights using this guide:
Once you've uninstalled the game, right-click the installer and select "Run as Administrator."
Still having issues?
If none of the above points helped, please submit a ticket to Player Support. In order to help us resolve your issue quickly, please include the following information in your ticket: