I have electric windows at the front of my mk3 ph1 Astra (L reg), and the driver-side window will not go up or down. You can hear the motor moving, but the window stays up. Then if you push the button to make it go up there is a terrible crunching noise. I tend just to leave it alone. But with summer fast approaching I'd quite like a window that works!

I've been told it's either come off its runners, or the window mechanism is bent.

I don't wanna open up the door, and not have a window afterwards. So I wanna have an idea of the problem and solution before I take the panel off.

It's DEFINATELY not the motor, as it whirrs away happily ;-)