1995 Ford Windstar Need Help

Not possible. The Windstar is a front-wheel drive vehicle; the Aerostar is a rear-wheel drive.
The tranny's are completely different.

Used tranny's from a junkyard cost between 350 to 500 dollars. Remember you need to take into account the labor to replace the tranny in the Windstar, too. And this is VERY labor intensive, to remove/replace Windstar transmissions.
By the time you get a used transmission and pay the labor of installation, you'll be at the 1,800++ mark.

I recommend getting yours rebuilt instead of going the junkyard route. Windstar tranny's tend to be problematic, so get yourself a good warranty, too. Cost runs around 1,800 to 2,300 dollars.

The reason the transmission (more appropriately called a transaxle) is so labor intensive to remove is because the subframe is in the way. Shop manuals recommend raising the vehicle to a height where the subframe can be removed from the body and lowered to expose the transaxle. I just find it easier to remove the engine and trans as a unit from the vehicle through the top, separate the two halves while it's hanging on the engine lift, re-attach a "better" transaxle, and install back to the chassis from the top.

. Or you need to simply determine if the vehicle as a whole is worth the expense.