The shock performance of hard disk drives has been a serious issue for Car PC. Since the vibration and disturbances from a car gives an adverse effect on a HDD of Car PC, it is necessary to protect a HDD from them. In this study, passive vibration attenuation system for a vehicle HDD was developed. Acceleration from the ground through the tire and suspension system was measured to figure out the frequency translated to Car PC. Critical frequency to Car PC was determined by exciting it with a shaker and measuring a data transmitting speed from HDD. A newly designed vibration attenuation system was fabricated to protect HDD from the acceleration. It was shown that the developed system had an excellent vibration attenuation ability.