How to backup several NASes to several Windows computers?


I have several NASes and several win computers. Each computer has each NAS as a mapped drive. I can’t install anything on NASes. Currently I manually copy (backup) files from NASes to local computer. On every win computer.

Can I backup mapped drive from NAS to the same computer? Do I have to install the server and the client to the same computer and do the backup? Do I have to do this process to all computers?

What would be the most efficient way, to backup NASes to Windows computers?