1:windows Server 2003 additional domain control upgrade to Windows Server 2003 primary domain control
(Because some services of the original domain controller are corrupted, the method of upgrading the standby domain control to primary domain control)
Https://wenku.baidu.com/view/f6289304ba1aa8114531d903.html
2:windows Server 2003 new alternate domain-controlled DNS migration to Windows Server 2003 new primary domain control
The target DNS server can also be a Windows Server 2003 series or a Windows Server 2008 series
http://blog.51cto.com/yaabb163/901375
A record is missing, you need to manually add a piece
3:windows Server 2003 domain-controlled migration to Windows Server R2
Https://wenku.baidu.com/view/0914f5e5ddccda38376bafb8.html
4:windows Server R2 domain controller migrated to Windows Server R2
Windows Server 2003 domain control migrates directly to 2012