1999 Buick Century power windows

I cannot roll down any of my windows, I discovered that the master control swithch was damaged, I replaced it and the windows still will not roll down, I checked the fuses and all relays, they appear to be in good order, when I push the window buttons for the passenger and rear windows there is no response, but the drivers window will make a "buzzing" noise when it is pushed, this has got me stumped..any suggestions?
THANKS in advance!
Mike