You can activate your Autodesk product either on startup or while you are running the product.
When you activate your product, you receive an activation code. If you activate through an Internet connection, your activation code is automatically retrieved from Autodesk and the product starts. If you do not have an active Internet connection, some products provide instructions for offline registration. Otherwise, you need to connect to the Internet to activate the product.
If you upgrade your product from an earlier version, you may need to provide your old serial number. For more information on activation, go to Autodesk Licensing and select the FAQ link.