Condition: we have a domain at the Windows Server 2003 (or 2003R2) functional level, and accordingly, we have domain controllers based on 2003/R2. But now the opportunity arises to install Windows Server 2008 (currently R2) and make them domain controllers.
What will we encounter first in this situation? The fact that you cannot promote a Windows Server 2008/R2 server to the role of domain controller without raising the domain functional level to 2008 (R2). In order to install even a single Active Directory domain controller based on Windows Server 2008, you will have to raise the level of the domain itself to a compatible one.
Where to get itAll the necessary tools are located on the Windows Server 2008 installation disc. Go to this disc, for example via "Explorer", and navigate to the support folder, and from there to adprep.
Inside this folder you will see a couple of exe files and a certain set of files. It is precisely these files and one of the exe files that we will need to raise the domain functional level.
Note. Your domain must be running in Windows Server 2000 Native or Server 2003 mode! Migration from NT4 domains is not supported - although I suspect those have long since died out due to their age.
Performing the steps1) Copy the tools
Obviously, we don't yet have a WS2008-level domain controller, since we are only about to raise the level of this very domain. So we take this entire folder and copy it to the domain controller holding the "Schema Master" role. After that, we log on to this controller under a domain administrator account with Schema Admins and Enterprise Admins rights.
2) Prepare the forest
Open a CMD window, navigate to the copied folder, and run the adprep.exe utility (if your Windows Server 2003 is 64-bit) or adprep32.exe (if you have the 32-bit Server 2003):
C:\adprep\adprep32.exe /forestprep
This command prepares the forest, making adjustments to it to work with 2008-level controllers, adding some new classes and attributes.
Read the notice carefully when it starts. For example, you may be asked to press the "C" key to continue.
3) Wait
Wait until the changes are replicated to all domain controllers. It's very important not to rush, but to wait and be sure that all DCs already know about the new schema version.
4) Prepare the domain
In the same window (if this same controller holds the infrastructure master role), enter the following command:
C:\adprep\adprep32.exe /domainprep
This command prepares this specific domain to work with the Server 2008 level.
If the infrastructure master is a different controller, you will need to copy the adprep folder to it as well and run the domain preparation from there.
4a) If you have more than one domain in the forest, perform step 4 for each domain.
5) Wait
Again wait until all the changes are replicated to all domain controllers.
6) Perform the policy update
Now copy the adprep folder to the domain controller holding the "Infrastructure Master" role and run the following command on it:
C:\adprep\adprep32.exe /domainprep /gpprep
6a) If you have more than one domain in the forest, perform step 6 for each domain.
7) Run:
C:\adprep\adprep32.exe /rodcprep
8) That's basically it. You can now promote the needed Windows Server 2008/R2 servers to the role of domain controllers.
Where are the logs?The logs of the adprep utility execution are located at:
\Windows\System32\Debug\adprep\logs
The utility creates a new log file for each run.
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