I am having problems setting up url rewrite rules in a subdomain. Let me explain: 1. I have a domain name www.paginatest.com. In the root web.config I have a rewriting rule <rule name="SubDomain" stopProcessing="false"> <match url="(.*)" /> <conditions> <add input="{HTTP_HOST}" pattern="^(?!www)(\w+)\.paginatest\.com$" /> </conditions> <action type="Rewrite" url="/sitios/{C:1}/{R:1}" /> </rule> This works fine. Every fo.paginatest.com points to /sitios/fo 2. Every subdomain is an isolate application in /sitios folder. Then /sitios/fo is an application. In its root folder I have a web.config with rewriting rules such as: <rule name="anytopic" stopProcessing="true"> <match url="^topics" /> <action type="Rewrite" url="/pages/topics.aspx" /> </rule> I expect than fo.paginatest.com/topics points to /sitios/fo/pages/topics.aspx but this does not work. Server says: Not such folder (topics) in server. Any idea? Thanks in advance and apologizes for my bad English