Fallout 4 runs just fine in my computer, but there is some checkered lines around some npc's. How can I solve this problem

Are you using steam? If so try and verify file integrity and reacquire files. Sounds to me like some texture files might of got corrupted in the download. If not, try re-updating your graphics drivers. I fall else fails, try and total reinstall of the game unless someone else has another/better suggestion. =]

Thanks Ammo