Motor Shield Programming

Hey, I recently bought an Adafruit Motor Shield 1.1, but i'm having problems programming it. Everytime I try to upload a program for 1 dc motor, it tells me it cant find the COM4 port, only the COM3, which doesnt finish uploading. Also, COM4 works fine when I detach the motor shield and play with LED's. I'm only a beginner, so I have no idea what to do.

You probably need more power.
Can you use an adapter ?

There is a jumper on the Adafruit Motor Shield for the power (connect it for power is same as Arduino Vin, remove it if both circuit boards have different power supply).
Do you use 5V motors ? How do you power it ?

I don't know if this is cross-posting, but it seems that you have a single problem. So it would be better if you started a single topic, instead of four.

I use 9v supply(6 AA)and my motors are 6-12v.Is that enough?