Driver side power window doesn't work. The passenger side worked for a while then, it stopped working also. I found thecircuit breaker box and pushed in the breaker for the windows. Now, the passenger side works but, not the driver side. Could it be a bad circuit breaker??

You say the driver window works? wouldn't be a main fuse or fusible link then -driver door locks and window wouldn't work either. Each door has a module inside (computer) . The driver door has a circuit breaker power feed an a fuse DDM fuse 10amp located in rear junction block circuit breaker is located in under hood maxi fuse block. The circuit breaker also feeds battery voltage to the other door modules too. PDM - passenger door module fuse 10amp located in the instrument panel fuse box and the RDM - rear door module RDM fuse 10amp located in the rear fuse box - under the back seat.

Each power window is connected to a permanent magnet motor. The motor raises or lowers the glass when the door module applies voltage to the motor. The direction the motor turns depends on the polarity of the supply voltage provided by the associated door module. The 2 front doors have their own separate modules. The rear seat contains a single module, which controls both of the rear power windows.
A serial digital communications link, called the simple bus interface, is used for communications between door modules and the driver's door power window switches. The use of serial digital communications allows the use of a single wire to convey switching information between the power door lock switch and the driver's door module (DDM). The serial communication is also used in order to transmit switching information from the DDM to the other 2 door modules.
The door modules apply battery voltage of the correct polarity to the respective window motor when any local, or power door lock switch, UP switch is operated, driving the window up. Battery voltage is applied to the respective window motor in the opposite polarity when any local, or power window switch, DOWN switch is operated, driving the window down.

Driver Door Module (DDM)
The driver's door module (DDM) directly controls the driver's door window motor and the express down window feature. The DDM sends window UP/DOWN messages received from the power door lock switch to the passenger door module (PDM) and to the rear door module (RDM) over the simple bus interface (SBI) line. The DDM also contains a class 2 data link which communicates with the other vehicle system modules. The left front power door locks and the outside power mirror are also controlled through the DDM.
Passenger Door Module (PDM)
The passenger door module (PDM) controls the passenger's door window motor. The PDM controls the passenger's door window directly from the right front power window switch or from instructions over the simple bus interface (SBI). The right front power door locks and the outside power mirror are also controlled through this module.
Rear Door Module (RDM)
The rear door module (RDM) controls both of the rear door window motors. The RDM controls the rear windows directly from the rear door window switches or from instructions over the simple bus interface (SBI).

Beings as everything that stopped working is on the passenger side, I'd think some wiring got disconnected or broken.

Doesn't use a fuse , ues a circuit breaker . These very rarely go bad .The right rear door works ? Uses same circuit breaker as front passenger door. The power windows an locks on your vehicle are controlled by electronic control modules . FPDM - front passenger door module , I would look for a broken orange wire inside the flex boot from the body to the front right passenger door . This is power supply to the passenger door module . Do you know what wiring diagrams are ? Free here http://www.bbbind.com/free-tsb

You also have Circuit Breakers for your windows, Or your Master Switch ,You can Test the Driver Control Switch or the rear switches by removing the Switches and using the connector Plug and a Jump wire try jumping accross the wires,if they go up or down you could have a Bad Switch,if nothing moves more than likely your Window Motor is bad. BUT first CHECK your Circuit Breakers ,It could be Labeled as accessery Relay or circuit Breaker.

Window fuse's and relay's may be up under passenger side dash or behind glove box.
Drivers door window gets used the most so it could be the motor, window switch, relay or fuse.
Could also be a broken wire in the rubber boot going from the door to the body. You will have to eliminate each till you find the culprit.
The motor and the relay are the most likely to cause this problem. Try swapping the relay with a working window relay. If it still doesn't work, remove the door panel and remove the window motor.
Turn the motor shaft in both directions by hand several turns. Then plug the motor in and see if the switch will now run the motor. Sometimes thats all it takes to get it working again. I have had to do this with brand new motors. If voltage is not present at the motor connector, either a bad switch or a broken wire exsists. Make sure to check for voltage coming to that windows switch. Actually, GM use's a circuit breaker type relay for each window and one fuse for all the circuit breakers.

The motor on the passenger side is shorted and is now tripping the circuit breaker. Odds are, the back window motor is also bad. You have to take the panel off to check the motor. You can power it directly to verify it has failed.

Probably motor and regulator, if you tried both switches on driver and passenger side suspect both window motor and regulator on passenger side sometimes while pressing the switch on the passenger side bang on the door panel inside and sometimes it may move if it does then suspect only the window motor.

2003 surbarban driver seat and passenger windows have common fuse/breaker under hood in fuse panel. 50 Amp fuse upper left of box, marked mped this is a big fuse not the little ones.

The RAP circuit breaker is directly behind the left side fuse panel. The chevy dealer acts like its a big secret and wants 75.00 to plug it in. You have to reach up under the dash and plug it in the BACK side of the left fuse panel. The diagram on the plastic cover is misleading. If you put the seat all the way back, you will have to lay on your back and with a flashlight you should look and you will see where it plugs in. This is on a 2002 chevy impala. Hope this helps.

Best Regards Jeff

if they only stoped working on the passengers side I would check the wirring going into passengers side door for a broken wire, or right at the passengers side kick panel.