How to fix lag issues in game

Alot of posts on people lagging when downloading or in the game, i was reading around about disabling p2p doing goofy stuff with folders, and nothing worked! well i went to my task manager and right clicked the application and set to "maximize" im not too computer illiterate but i have some knowledge and it fixed all my issues with the game completely! Please respond if this helped you too, so i know that my suggestion worked