Hi Mountain cur,
Windage is most always adjusted at your longest distance first. This is because if it is off at all, it is magnified as your distance is increased. If your arrow rest is a fraction of an inch off center, it will cause your windage to walk left or right as you increase your distance, so my suggestion would be to move out to 80 or 90 yards and then make micro-adjustments moving only your arrow rest the smallest amount possible until you are dead center at this distance.
Once finished immediately move back into 20 yards to insure you are still dead center at 20 yards. If so, you are done. If not, this means that your nocking point and arrow rest are not aligned properly and you will need to adjust the rest until they are aligned perfectly to one another.
During these adjustments your scopes windage should remain centered at the mid point of it's adjustable range. Windage adjustments on your scope should only be used once you insure that your alignment between your nocking point and arrow rest has been set perfectly with one another.
Regards,
Jon Henry