On Windows, even if we have bash (which is provided , for example, by the GoW project) we don't have the tools required by validate-svg.sh to actually run. We'd need to also ensure the unixy 'find' command (not the Windows 'find' command) as well as xmllint.
For now let's not even bother on Windows.
A better solution is to write a new portable script in Python . and also you need to make sure xmllint is available.