I had the same problem as you all with the passenger window on my laguna, it went down only an inch or so then constantly pressing the up down button, it eventually went up again, i got mine refurbished by a guy on
Renault Laguna II Electric Window Regulator *REPAIR*
item number 180221554030
fairly easy to remove and reinstall with his clear pictured instructions,
go on give him a whirl and take the trouble out of how to do it by getting it done for a small price.