S10 Blazer window

Take off the door panel, then you will most likely find a small round roller that is broken(it rolls in the track and is mounted on the end of the arm) A new one can be had from the dealer or glass shop. It will pop on the arm with the aid of plyers or channel locks.

The parts that move the window up and down are fine. Its the little plastic bits that keep the window upright. The leading edge has one and the trailing edge has two.