Microsoft has supplied an update for Windows Server 2003 that enables support for activating Windows 7 and Server 2008 R2 computers. Download the update from Microsoft.Without this update, if you attempt to activate a Windows 7 or Server 2008 R2 computer using your Server 2003 KMS, you’ll get an error stating that the KMS key is invalid. Install this update to extend support for Key Management Service (KMS) to provide activation for Windows 7 and Windows Server 2008 R2. After you install this item, you may have to restart your computer.
Activating Windows 7 and Server 2008 R2 computers