<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <defaultDocument>
            <files>
                <clear />
                <add value="index.asp" />
                <add value="Default.htm" />
            </files>
        </defaultDocument>
    </system.webServer>
</configuration>

來自：https://www.landui.com/help/show-8311.html

允許目錄瀏覽

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <system.webServer>
        <directoryBrowse enabled="true" />
    </system.webServer>
</configuration>

其它設置參考：http://www.cnblogs.com/enfp/articles/7718264.html

[轉][C#]Web.config 相關配置