If you are getting this Error with Intelligencia.UrlRewriter and IIS 5/6,Follow these simple steps.
2-Select web site you are working on.
3-Right click on it and select properties.
4-Click on "Configuration" button .
Now we need to tell IIS that aspnet_isapi.dll should also execute those pages which has no aspx extension.
5-From Application Mapping tab , click Add button,in application mapping pop window,browse
,C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll in executable .
6.type .* in extension.
7.Uncheck the"Check that the file exists".
Note all web.config configuration should also be done according to rewriter configuration.