It removes mouse acceleration from windows all together. I posted it in the Tips thread on the source forum. Handy for making consistent turns to the enemy. Often times when you turn towards a person if you move the mouse too fast the acceleration inherent in movement will make your crosshair zoom past them. The mouse fix will enable you to make concise and consistent 180, 90 , etc. degree turns to whever with out having to adjust for missing the enemy.
