title: ColdFusion 11 installation unsuccessful
body: <p>I installed ColdFusion 11 Developer version (downloaded from Adobe site 3 months trial) on Windows 8.1 and IIS7. I got this error when trying to open the ColdFusion administrator (see below). Is there a step by step example on how to fix this?</p>
  
  <pre><code>HTTP Error 500.19 - Internal Server Error
  The requested page cannot be accessed because the related configuration data for the page is invalid.
  Detailed Error Information:
  Module         CustomErrorModule
  Notification   SendResponse
  Handler        cfmHandler
  Error Code     0x800700b7
  Config Error   Cannot add duplicate collection entry of type 'mimeMap' with unique key attribute 'fileExtension' set to '.air'
  Config File    \localhost\?\C:\inetpub\wwwroot\web.config
  Requested URL  localhost:80/administrator/CFIDE/index.cfm
  Physical Path  C:\inetpub\wwwroot\administrator\CFIDE\index.cfm
  Logon Method   Anonymous
  Logon User     Anonymous
  Config Source:
        4: &lt;staticContent&gt;
        5:  &lt;mimeMap fileExtension=".air" mimeType="application/vnd.adobe.air-
              application-installer-package+zip" /&gt;
        6: &lt;/staticContent&gt;
  </code></pre>