Image optimizer for web - offline?

Question

Adobe Photoshop

Good afternoon!
A friend has wordpress, he made a backup, 15 gigs. Well, not much if you do not take into account that there are not so many posts.
that's not the point.
everyone who has come across this cms knows uploads/yy/XX/image.
in short what is the point.
he loaded pictures for miniatures, etc. weighing 500 kilos is at best. sometimes and above 5 meters pictures.
and all this resulted in the fact that the site weighs a lot, etc.
Maybe someone will tell you a program for Windows, which will go through the folders and recompress the pictures for the web.
I think so 100% there is some kind of script for photoshop
, etc.
Do not offer online services. Of course, you can use them too, but the task is to make the program work with the entire folder structure
by itself and press it.
Tell me

Answer 1

faststone - there is a batch processing function.

Answer 2

How to reduce thousands of pictures in all subfolders?
Under Windows - I doubt that there is such a thing with the same flexibility as on Linux