doesn't seem to have enough power to roll windows up or down

I have a 1991 chevy cavalier convertible . Their doesn't seem to have enough power to roll windows up or down. Could they need to be replaced or a different problem?

The car sat for 3 years. The windows want to roll down but stop about halfway. And labor hard both ways. I've greased drivers side to no avail. Is their something with the convertible lift that has something to do with it