Setting up DNS Forwarding for Windows Server 2012 and 2012 R2
The basic instructions are as follows, with screenshots of what you should expect to see included below.
4. Add OpenDNS addresses in the IP address list.
Please write down your current DNS settings before switching to OpenDNS, in case you want to return to your old settings for any reason.
The addresses for Open DNS are:
Then click OK.
6. Click OK once more