I’m testing an install of DotNetNuke on IIS 7 and ran into an error when trying to start the site.
The WebResource.axd handler must be registered
I tried following some guides online to add the handlers to the >system.webserver> section which is there for IIS in the web.config but I couldn’t get them to work so I just switched the application pool to classic mode. I’d rather run in integrated, I hate running something as up to date as DNN on an IIS 7 server in basically IIS 6 mode; but for now this works. So to get around this error just switch your app pool in IIS 7 to classic mode and then restart it. Below is a guide on how to do that.
http://support.gearhost.com/KB/a381/change-managed-pipeline-mode-in-iis-7.aspx