power windows issue on 2001 BMW 330i

loud screeching/glass broken noise. one side opens and closes with noise. other side opens but won't close, have to manually raise it. Is it regulator or motor?

3 answers
These cars have a little plastic guide that breaks and sometimes causes the window to exhibit these problems.
In these cases, it's almost always a problem with the regulator. Problems with the motors are more uncommon. The labor to replace is very similar, though. If it's a problem with the motor, you will be out the additional part cost.
I just experienced this problem a week ago, it was a pulley that was broken.