No response most likely means that Discovery tried to ping the machine and did not get a response.
NoAccess has more causes. For example if Discovery does not, by default, see port 135 open then it will not try WMI or RemQuery. If you look at the DiscoveryAccess what does the session results show?
Thanks Andrew for quick response.
But I can see that port 135 is open and the Windows machine is up and running.
and I am also able to take RDP from Proxy server.
Okay - but you have not provided any of the requested additional information. Without this it makes it very hard to answer your question.