Migration and Upgrade
You can migrate sites based on a previous version of Microsoft Commerce Server to Commerce Server 2009 R2. Migrating from an earlier version of Microsoft Commerce Server to Commerce Server 2009 R2 involves backing up your existing sites, upgrading your hardware and software environment to meet Commerce Server 2009 R2 requirements, upgrading your data and schema (data migration), and updating existing site code to work with Commerce Server 2009 R2 (site code migration). Site code migration varies in complexity, depending on the environment you are migrating from.
All sites operating on Commerce Server 2009 R2 must be written in ASP.NET. Migration of Commerce Server sites written in Microsoft Active Server Pages (ASP) is not supported.