Error Messages Property Sheet
Use this property sheet to customize HTTP errors that are sent to clients when Web server errors occur. Administrators can use standard HTTP 1.1 errors, detailed custom error files that IIS provides, or they can create their own custom error files.
To change the properties of a custom error message, select the HTTP error and select either Default, File, or URL from the Type column.
If you select the Default option, the standard HTTP 1.1 error will be returned to clients. The text of the default HTTP 1.1 error appears in the Contents column.
If you select the File option, enter the local path of the custom error file.
If you select the URL option, enter the path to the URL beginning with the virtual directory name, as in /virdir1/errors/404.htm, for example; this URL must exist on a local server.