Resolving "DNS name does not exist" activating Windows 8?
Microosoft Knowledge Base 929826 article suggests it's looking for a KMS host server.
Make sure you're on (or VPNed into) your work or school campus when activating. If that doesn't apply to you there's a method listed on that article that shows how to use your MAK instead:
- Run the command prompt as an administrator
- Enter
slmgr -ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxxwherexxxxx-xxxxx-xxxxx-xxxxx-xxxxxis your product key.
Then try activating again.