Question: how to upgrade windows 2003 domain controller to 2012?
Answer: Raise and Verify AD Forest Functional Levels. Pro Tip No. ...  Step 1: Prepare a Windows Server 2012 R2 Server. Begin with the basics. ...  Step 2: Add the AD DS Role on the New Server. ...  Step 3: Promote the Windows Server 2012 R2 Server to a DC. ...  Step 4: Transfer the FSMO Roles. ...  Step 5: Decommission the Windows Server 2003 DC.