Yeah I've had problems with this:
First check the thermo fuse, if both windows are failing then this might be the cause,
You can keep the power, current and resistence through the switch plug, check with Hayes for which pins should be checked togerher,
If the fuse and pins seem fine then it could be the switch,
If you get an open circut across the motor it could be either the wiring to the motor or the motor itself.
Take the door card of unplug the motor and check for a circuit across there, if you have a circuit you can alway see if the motor works by spplying 12v to it, switch the polarity to change the direction.
If your motors don't work then you need news ones.
You might find (as I did) that one switch and one motor are working (but on different sides, putting the working switch with the motor got one side working, still working on the other side.