Avoid disabling CompatTelRunner except as a temporary measure to improve performance. It can be temporarily stopped through the task manager. It will restart when accessing a network.
My experience, the Compatelrunner will hog disk time and affect performance (jerking mouse motion, stalled programs) after installing a major update or just before an important update.
The computer will run normally again after several hours or longer when the program and virus scanner completes their inventory processes.