Unless you are actually connecting the servos to a 5 V power cable (like the disk drives) inside the computer itself, the USB port is not going to provide appropriate power for a servo, let alone more than one.
That is why people keep on asking you. 
Unless you are actually connecting the servos to a 5 V power cable (like the disk drives) inside the computer itself, the USB port is not going to provide appropriate power for a servo, let alone more than one.
That is why people keep on asking you.