Why Use the Commerce Server 2007 Upgrade Wizard?
Use the Upgrade Wizard to upgrade global resources, site resources, and site data from Commerce Server 2002 and Commerce Server 2000 to Commerce Server 2007. If you prompt it, the Upgrade Wizard will delete resources that have been made obsolete in Commerce Server 2007, such as Predictor and Business Desk Security. It will upgrade site resources such as Catalogs, Campaigns, and Marketing. It will even review your catalog data and check for unauthorized conditions. It also updates the version resource information for resources that have not changed in the release.
After you upgrade your site, you should remove additional resources according to the instructions in Post Migration Data Management.