When you attempt to run the Active Directory Installation Wizard on your Windows Server 2003 R2 computer, the installation doesn't complete. You may receive:

The Active Directory Installation Wizard cannot continue because the forest is not prepared for installing Windows Server 2003. Use the Adprep command-line tool to prepare both the forest and the domain. For more information about using the Adprep, see Active Directory Help.

The version of the Active Directory schema of the source forest is not compatible with the version of Active Directory on this computer.

This behavior will occur if you haven't updated the schema to the R2 schema extensions. If you ran ADPrep.exe /forestprep from the original CD-ROM instead of from the R2 CD-ROM, the schema has not been updated for R2.

To correct this problem:

1. Mount the Windows Server 2003 R2 installation CD in the CD-ROM or DVD-ROM drive.

2. Type <Drive:>\CMPNENTS\R2\ADPREP\adprep.exe /forestprep and press Enter.

NOTE: The ADPrep.exe tool for Windows Server 2003 R2 is version 5.2.3790.2075.

To verify the operating system support level of the schema, run SchemaSL.bat SL, where SL is a call directed environment variable that will contain the support level:

            ?? is unknown
            13 is a Windows 2000 support level
            30 is a Windows Server 2003 support level
            31 is a Windows Server 2003 R2 support level

NOTE: SchemaSL.bat uses ADFind.exe and DomainDN.bat.

SchemaSL.bat contains:

@echo off
if \{%1\}==\{\} @echo Syntax: SchemaSL SL&goto :EOF
setlocal
call DomainDN DN
Set SL= objectVersion: ??
set key="cn=schema,cn=configuration,%DN%"
call :Quiet>nul 2>&1
endlocal&set %1=%SL:~16,2%
goto :EOF
:Quiet
for /f "Tokens=*" %%a in ('adfind -nodn -noctl -b %key% objectVersion^|find "objectVersion:"') do (
 set SL=%%a
)