92 wagon,drive side front window can lower down properly, but it can only move up slowly, sometimes does not move. Need help! Thanks.

new window regulator

new window regulator

So each window is controlled by a window regulator? because other windows work properly.

yup, the window regulator is the entire unit (motor, arms, gears, etc.) inside the door. Each door/window has its own. Be sure that is what it is before you go through all that trouble though, somewhat tedious work. Not worth it if its not the problem.