Two of my 4 power windows go up very crooked and jam and then require user assistance to get them to go up in a level manner so they close or to even get them back in the track so they close. One of the them goes down real crooked too. What causes this and is it something I can fix?
It sounds like the window regulators are either loose or worn out.
The only way to find out which it is, is to remove the inner door panel.
Is this a 96 or older Impala? if yes, these cars had some simple plastic wheels that were a part of the window regulator(2 per regulator, they were more ovals than wheels but they can be replaced with wheels), they always break. If you get a bit inventive you can fix the windows for pennies and some time, unless you are all thumbs.
Very,very common and money making (for the mechanic) problem.