How to redirect .html files in the old ASP.NET (nop 3.xx)?

Add this new handler  in the web.config file

    <handlers>
      <add name="SitemapXml" path="sitemap*.xml" verb="*" type="System.Web.Routing.UrlRoutingModule" resourceType="Unspecified" preCondition="integratedMode" />

      <add name="AllhtmlFiles" path="*.html" verb="*" type="System.Web.Routing.UrlRoutingModule" resourceType="Unspecified" preCondition="integratedMode" />