Upgrading Windows NT 4.0 domain to Windows 2008 domain

Migration for NT 4.0 Domain to Windows Server 2008 Domain
Upgrading WinNT 4.0 domain to Windows 2008 domain
How to upgrade WINNT 4.0 domain to Windows 2008 domain.


We cannot directly upgrade Windows NT4.0 domain to Windows Server 2008 domain.

In order to smoothly upgrade the domain, here are two recommended upgrade
routes for your reference.

Route 1.

A. Upgrade Windows NT 4.0-Based PDC to Windows Server 2003-Based domain
controller.

For more detail steps, please refer to:

How To Upgrade a Windows NT 4.0-Based PDC to a Windows Server 2003-Based
Domain Controller
http://support.microsoft.com/kb/326209

Moving from Windows NT 4.0 Server to Windows Server 2003
http://download.microsoft.com/download/2/c/3/2c3cc747-a843-4a23-b665-8bd62fa
bbc1e/How-to-Migrate-from-NT-to-WS2003.pdf

B. Then upgrade Windows Server 2003 based domain to Windows Server 2008
domain.

For more detail steps, please refer to:

Upgrading Active Directory Domains to Windows Server 2008 AD DS Domains
http://technet2.microsoft.com/windowsserver2008/en/library/9c91be5f-df14-40b
2-b176-2b1852a51e611033.mspx?mfr=true

Route 2.

We may also use ADMT 3.1 to migrate from Windows NT 4.0 source domain to
Windows Server 2008 domain.

Since ADMT 3.1 Beta has been available for public evaluation. If you are
interested, please refer to the steps provided in the following below link
to apply for ADMT 3.1 Beta.

ADMT 3.1 Beta
http://blogs.technet.com/ad/archive/2008/04/22/admt-3-1-beta.aspx

Upgrading Windows 2003 Active Directory Domain Services to Windows 2012 Active Directory Domain Services

"Can we upgrade of Windows 2003 Active Directory directly into Windows 2012 Active Directory?".  Remember we are not talking about upgrading the OS from Windows 2003 to Windows 2012, we are talking about upgrading Active Directory. 

The two answers to this question are given below. 

A) The answer is NO if you are planning to insert Windows 2012 OS CD into Windows 2003 DC and upgrade it to a Windows 2012 DC. This'll not work. Please read the excerpt from Microsoft Technet which is given below. 

'You cannot upgrade domain controllers that run Windows Server 2003. To replace them, install domain controllers that run Windows Server 2012 in the domain, and then remove the domain controllers that are Windows Server 2003.'

B) The answer is YES if you use the method mentioned below. It'll help you avoid first upgrading Windows 2003 AD to Windows 2008 AD and then into Windows 2012 AD. The steps mentioned here have been tested in the LAB and have helped us to move from Windows 2003 AD to Windows 2012 AD. The default AD functional levels i.e. Forest Functional level and Domain functional level were found to be, "Windows 2008" though. If needed this can be raised to Windows 2012 and this is an irreversible change.

Steps to upgrade Windows 2003 Active Directory to Windows 2012 Active Directory. 

1. Install one or more Windows 2012 Servers in your existing Windows 2003 AD domain. 
2. Make it a member server of the domain. 
3. Please ensure that your domain functional level and forest functional level are raised to Windows 2003 native mode. Please do take all the precautions before making this irreversible change. Once done please log on to newly Windows 2012 server. 
4. Browse the OS CD\DVD\ISO and go into the Support Tools --> ADPREP folder. 
5. Open Command Prompt and change the directory to the location of ADPREP folder. 
6. Run the commands adprep /forestprep followed by adprep /domainprep and adprep /gpprep. This prepares your Windows 2003 AD forest and domain for Windows 2012 AD. 
7. Add the Active Directory role into the Windows 2012 member server. 
8. Install Active directory and its dependencies. 
9. Allow the replication to complete. Verify the same before proceeding to next step. 
10. Transfer the Active directory FSMO roles on Windows 2003 domain controllers to Windows 2012 domain controllers. To take the necessary precautions before doing the same and ensure that the roles are transferred based on the best practices recommendations of Microsoft. 
11. Once you are sure that all the AD FSMO roles has been transferred to a Windows  2012 DC or domain controllers follow the next step. 
12. You can go ahead and demote the Windows 2003 DC gracefully by running DCPROMO on them. Don't forget to un-check the check box described as, "This is the last domain controller on the domain".  

Please do take all the precautions like studying your environment and working of dependent applications followed by rigorous tests in your lab before taking up such upgrades in production environment.