If you are upgrading to Cisco Unity 8.0 and reinstalling software on the Cisco Unity server (for example, because you are replacing the server or upgrading to Windows Server 2003), you must use the Data Store 2000 disc that ships with Cisco Unity 8.0. The Data Store 2000 disc that shipped with earlier versions of Cisco Unity has a different directory structure, and the Cisco Unity System Setup Assistant, which guides you through installing and configuring Cisco Unity 8.0, will not recognize the Data Store 2000 disc that shipped with Cisco Unity 7.x and earlier. (If you paid for an upgrade to SQL Server 2005, we will ship you a Data Store 2005 disc with the rest of your Cisco Unity software.)
The Cisco Unity 8.0 version of the Data Store 2000 disc is not available for download on Cisco.com. To perform an upgrade that requires reinstalling software on the Cisco Unity server, you must either wait for the Cisco Unity 8.0 installation discs to arrive or manually install SQL Server 2000 or MSDE 2000. Manually installing the application is not documented and, therefore, not supported.
There's your answer. You need to order the upgrade kit from Cisco in order to get the proper DVD.