My driver side window does not go up and down. I took the whole window assembly apart and found nothing wrong, I took the switch from the passenger side and it goes up and down with that switch. I got a new switch put it in and it does not work either. Both switches will work all the other windows except for the driver side window. I know the motor is not bad because I tested it with the passenger side switch. I have check fuses 20,24 but they are both good. So Anyone have any ideas what could be cause this to malfunction like this?

you need a new regulator, my 2001 x5 just had this happen back in april of this year, hope this helps bring it to the bmw dealer if you want to confirm it...