Product keys are required for installation of Autodesk products and are used to differentiate products that are both sold independently and as part of a product suite. For example, installing AutoCAD 2012 as a point product requires product key 001D1, but installing AutoCAD 2012 from the Autodesk Product Design Suite Ultimate 2012 requires product key 781D1. The same version of AutoCAD is in both software packages but the product key differentiates one package from the other. Note: Please ensure you are using the correct product key for the Autodesk product and version you are installing. Entering an incorrect product key will result in activation errors for that product.