The DNS server machine currently has no DNS domain name. Its DNS name is a single label hostname with no domain (example: ...

The DNS server machine currently has no DNS domain name.  Its DNS name is a single  label hostname with no domain (example:  "host" rather than "host.microsoft.com").  
  
You might have forgotten to configure a primary DNS domain for the server computer.  For more information, see either "DNS server log reference" or "To configure the  primary DNS suffix for a client computer" in the online Help.  
  
While the DNS server has only a single label name, all zones created will have  default records (SOA and NS) created using only this single label name for the  server's hostname.  This can lead to incorrect and failed referrals when clients  and other DNS servers use these records to locate this server by name.  
  
To correct this problem:  
  1) open Control Panel  
  2) open System applet  
  3) select Computer Name tab  
  4) click the "Change" button and join the computer to a domain or workgroup; this name will be used as your DNS domain name  
  5) reboot to initialize with new domain name  
  
After reboot, the DNS server will attempt to fix up default records, substituting  new DNS name of this server, for old single label name.  However, you should  review to make sure zone's SOA and NS records now properly use correct  domain name of this server.