Validator fails in local network

Hi I was able to install validator on local network on Windows Server 2008but looks like it always tries to connect to www.w3.org and validation fails , even document is 100% valid
I would like to limit server and do not allow to send request from local network.How I understand it wants to get DTD packages.
Any suggestions?
Validation Output: 10 Errors Line 1, Column 121: error connecting to "www..w3.org" (error number 10060)….0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

All the bests!Sincerely,
Armen Kirakosyanhttp://www.barracudagames.com