You use the Product License Activation wizard to activate the product.
The first time you start AutoCAD, the Product License Activation wizard is displayed. You can either activate AutoCAD at that time, or Try AutoCAD and activate it later. Until you register and enter a valid activation code for AutoCAD, you are operating the program in trial mode and the Product License Activation wizard is displayed for 30 days from the first time that you run the program.
If after 30 days of running AutoCAD in trial mode you have not registered and provided a valid activation code, your only option is to register and activate AutoCAD. You will not be able to run in trial mode after the 30 days expires. Once you register and activate AutoCAD, the Product License Activation wizard is no longer displayed.
The fastest and most reliable way to register and activate your product is by using the Internet. Simply enter your registration information and send it to Autodesk over the Internet. Once you submit your information, registration and activation occur quickly.