When your working on the inside of a computer its always best to ground yourself. You can ground yourself by using whats called an anti-static wrist strap.
An anti static wrist strap
Anti-static wrist straps are available for purchase at most electronic stores. They work by putting one end on your wrist and the other end on the metal frame of the computer. This grounds your body to the computer thus making sure you and the computer are at the same electrical potential