Well, for one thing it is much easier going down than up. Ever notice
how much harder it is to climb stairs.
If the mechanism is bound up and rusty, the window will stop moving. If
it doesn't even try to move even with a little manual assistance, then
the switch likely bad. Since you say "windowS" instead of wndow, I
presume it's the switch.
I'm guessing that these are the windows in your vehicle rather than the
Patient: Doctor, it hurts.
Patient: You tell me. You're the doctor.