Step-By-Step: Active Directory Migration from Windows Server 2008 R2 to Windows Server 2012

Prerequisites

1. Download Windows Server 2012. If you plan on completing this Step-By-Step in a virtual lab, it is recommended to download the FREE Hyper-V Server 2012 first.
    
2. Complete a full backup of your existing server. Better to be safe than sorry.
    
3. Check the Schema version of AD DS (Before adprep) by running regedit, navigating to Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\NTDS\Parameters and noting the current Schema version.

Step 1: Preparing your existing forest via the adprep command
 

1. Insert the Windows Server 2012 DVD into the DVD drive of the Windows Server 2008 R2 AD DS.
   
   
2. Open command prompt, and type adprep /forestprep and press enter.
    
   
3. Check the Schema version of AD DS (After adprep) by running regedit, navigating to Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\NTDS\Parameters and noting the current Schema version.
    
   

Step 2: Promoting the Windows Server 2012 Server domain controller
 

1. Complete Step-By-Step: Adding a Windows Server 2012 Domain Controller to an Existing Windows Server 2003 network

Step 3: Verify the new Windows Server 2012 Domain Controller

1. Open Active Directory Users and Computers, expand <Your Domain> and click the Domain Controller OU to verify your server is listed.
    
2. Open DNS Manager, right-click on <Your Domain>, select Properties and then click Name Servers Tab. Verify that your server is listed in Name Servers: lists.
    
3. Open Active Directory Sites and Services; verify that your server is listed in Servers under Default-First-Site-Name.

Step 4: Transferring the Flexible Single Master Operations (FSMO) Role

1. Open the Active Directory Users and Computers console on your new Windows Server 2012 computer.
2. Right click your domain and select Operations Masters in the sub menu.
3. In the Operations Masters window, ensure the RID tab is selected.
4. Select the Change button.
   
   
5. Select Yes when asked about transferring the operations master role.
6. Once the operations master role has successfully transferred, click OK to continue.
7. Ensure the Operations Master box now shows your new 2012 Windows Server.
8. Repeat steps 4 to 6 for the PDC and Infrastructure tabs.
9. Once completed, click Close to close the Operations Masters window.
10. Close the Active Directory Users and Computers window.

Step 5: Removing the Windows 2008 R2 domain controller

1. On the Windows 2008 R2 server click Start, Click Run, type dcpromo, then click OK.
    
2. After the Welcome to the Active Directory Installation Wizard page, be sure to leave the Delete the domain because this server is the last domain controller in the domain unchecked.
    
3. On the Administrator Password Page, enter your password and click Next.
    
4. On the Summary page, click Next, wait for the process to end, then click Finish.
    
5. On the Completing the Active Directory Domain Services Installation Wizard, click Finish.
    
6. On the Active Directory Domain Services Installation Wizard page, click Restart Now to Restart the server.
    
7. After the reboot is completed, delete the Windows Server 2008 R2 server from the domain to a workgroup and remove any unnecessary record from Active Directory Sites and Services.