Windows 2012 with IIS 8 Using IIS Manager I have the following settings. Status Code: 404 Redirect: http//www.MySite.com/err404.aspx (err404.aspx is on the server and the path is correct) Under Feature Settings. Mode: On Redirect Mode: ResponseRedirect Absolute URL: http://www.MySite.com/err404.aspx In web.config I have: <customErrors mode="On" defaultRedirect="error.htm"> <error statusCode="500" redirect="err500.aspx"/> <error statusCode="404" redirect="err404.aspx"/> </customErrors> http://MySite.com/test returns the default 404 error page for IIS (IIS 8.0 Detailed Error - 404.0 - Not Found) , IIS is not redirecting to my err404.aspx file it is using it's own 404 page. It is as though I have nothing set, it is acting in the default mode. What am I missing? Why is IIS not redirecting to my err404.aspx page? All help is greatly appreciated.