Just as others have suggested, Power Options on Control Panel is good enough for what you wanted to achieve.

But if you want something fancier and advanced try ThrottleStop. You can use it to set your CPU multiplier.

Guide
http://forum.notebookreview.com/threads/th...p-guide.531329/

Download
https://www.techpowerup.com/downloads/2288/...ottlestop-6-00/