Q:

Cannot connect to Active Directory Domain Controller

I have been working since last night to get our shared hosting machines connected through Active Directory (long overdue) but am running into an issue with clients connecting to the Domain Controller.
I have setup the Domain Controller and the DNS Server on our "Master" machine, following the guide found HERE. Everything appears to be working fine, but when I go to another machine, and attempt to join the domain, I get the error...
"The following error occurred attempting to join the domain "xfactorservers.local": The network path was not found".
I have set the Preferred DNS server on the NIC to the IP of the one running on the server. It appears to be finding it, so I don't know what is causing this issue.

A:

Get rid of the Google DNS servers on the NIC's of your server. Those should be added to the forwarders of your DNS server, they should not be configured as DNS servers for the DNS client on the server, which is what you have by having them configured as DNS servers on the NIC's.
Do the servers in question have direct connectivity to each other? Your server is using a routable ip address and I'm assuming your other servers do to. What is the path from one server to another as returned by tracert?
Are there firewalls on or in between these servers? If there is then you're likely to need to configure some rules on the firewalls to allow AD communication. Here's a document from MS that explains domain communication through a firewall. It was written for W2K but It should still be relevant for W2K8:

http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=16797

