Activation is the process of verifying the serial number and product key of an Autodesk product, and licensing it to run on a specific computer. If a license administrator registers products with Autodesk before they are used, then activation occurs automatically as users start the products.
Activation cannot occur if the serial number and product key combination is invalid, or if the user is disconnected from the Internet. In such cases, the user must contact Autodesk to resolve the situation. Some products provide instructions for offline registration. This can involve generating a request code, sending it to Autodesk, and then receiving an activation code to enter on a product screen to complete the activation process.
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.