amd e1

My Crucial 2X4GB DDR3L is shown half of it's speed 577Mhz on the system and supposed to be 1066Mhz on each Ram Module when I tried different Ram like 2GB with 4GB only this time is now shown 667Mhz. How can I restore it to the original Speed 1066Mhz My laptop is acer Aspire E1-15 /...