Whats wrong with my Micro Innovation Optical mouse?!?! PLEASE HELP!?

Hey there, i just found my micro innovation PD430P Optical mouse with PS/2 Port. When i hooked this up, the mouse on the computer wouldnt move. The port fits in fine, and the light on the optical mouse is on, but it doesnt seem to move, can someone help!?! I tried looking for the drivers, but didn't find any. So whats wrong?