What do you do when your car will not start after you replace the distributor?

If the starter is still rotating the crankshaft upon turning the key in the ignition, AND there is a charge from the ignition coil to the distributor, the problem is most likely that 1. The distributor is improperly timed and/or calibrated for the engine in which it is placed, 2. The distributor is the incorrect type for the engine it is attached to, or 3. the mechanical linkages that spin the rotor are defective or incorrectly installed.