It sounds like the motor is going. Unfortunately unless you can get to the motor, there's probably not much you can do.
I've had luck with tapping it with a small mallet or the handle of a screwdriver just to get the window up, but then I recommend that they replace the motor. There is no guarantee that it will work the next time.
You will probably have to take it to a shop to get it fixed. If you can hear the motor running but the window doesn't move, it may be off the track. Sometimes if you can grab the glass you can position it back into the track and put the window up.
Again, either way, get it looked at because the same thing could happen again. Hope this helps.
〉 Answered on Feb 11th, 2008 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines