The issue is that it's seeing \\nawinfs06 as /nawinfs06 because it typically strips out backslashes and converts them to forward slashes during install-time.

You can probably work around it by editing your configure.php files after you've finished installation and altering the path settings from /nawinfs06 back to \\nawinfs06

Or, you can probably get around it by running it from a physical drive on your server directly, instead of serving it off an external server like you're doing.