In this example I had an old Windows 2003 Server that was my file server. Its name was FS01. I created a new Server 2012 FileServer with name of FS02. I was demoting the FS01 server and wanted FS02 to allow share access using the old name. Here is what I did.

  1. Create a new CNAME for FS01 to FS01
  2. Navigate to HKLM\SYSTEM\CurrentControlSet\Service\LanmanServer\Parameters\
    1. Create a new DWORD value named “DisableStrictNameChecking” and set its value to 1
    2. Create a new Multi-String Value named “OptionalNames” and add all optional names like the NETBIOS and FQDN
  3. Reboot Computer
  4. Verify that there are no other Computer Objects in AD named FS01, if so delete them.
  5. Run Powershell as an Administrator and run the following
    1. netdom computername FS02 /add:FS01
    2. netdom computername FS02 /


Now your new server should respond to both names and allow you to access shares from both names.