How can you tell if the window regulator is bad or if it is the switch?

Symptoms:

Driver window does not move with switch
I can connect power to the window motor and it goes up and down
Passenger window works with passenger switch, but not with driver switch.

To me it seems the driver switch is the problem, but want to know for sure before buying.

 

Make and Model of the vehicle?

Sound like a bad master switch since the motor is working when you connect 12 volts from the outside source.