The Patch level (Service Pack) of the remote IIS server appears to be lower than the current IIS service pack level. As each service pack typically contains many security patches, the server may be at risk. Caveat: This test makes assumptions of the remote patch level based on static return values (Content-Length) within the IIS Servers 404 error message. As such, the test can not be totally reliable and should be manually confirmed.
Ensure that the server is running the latest stable Service Pack