Windows Server 2003 R2 was released a while back and along with all the new features come some schema changes. Due to these schema changes, if you attempt to promote a Windows Server 2003 R2 server to a DC you will get an error. These schema upgrades are also required if you wish to use some of the new features included with R2.

Windows Server 2003 R2 includes many new features including: 

• New DFS Replication Services 
• Print Management Console 
• Identity Management For UNIX

Just like when you upgrade your schema to add a Windows 2003 DC into your Windows 2000 domain, you must first run ADPrep in order to upgrade the AD schema to support the Windows 2003 DC. To prep your schema for R2, the process is very similar to upgrading the 2000 schema, so similar that the tool used is the same! To upgrade the schema insert the 2003 R2 install media (the 2nd CD with the R2 components) into the CD drive on the Schema Master FSMO role holder and run the following command:

cd X:\cmpnents\R2\adprep adprep /forestprep

Note: X = the CD drive with the R2 install CD

You will be prompted with a warning. If you are running this on a 2000 DC, you need to be running 2000 SP1 at a minimum. Windows 2000 SP2/3/4 need to have a patch installed. If everything is OK, press C to start the upgrade process.

The process is a relativly quick one, there are only 139 changes made.

You can now install the new features of R2 (that require the schema updates) or install an R2 server as a DC in your 2000 or 2003 domain.