I know that Sef on here had a problem with his window on the day we left for Alsace, the cure I believe was to give the door panel a sharp bang near the speaker grill.
This gem was obtained from one of the other forums and worked a treat.
It could be a fuse and you should have a pair of tweezers in the fuse box that you use to take the fuses out. The fuse box is located inside the car and the drivers side window looks like Fuse number 19 and is a 30 amp fuse (the passenger window is fuse number 1 and is also a 30 amp fuse).