The legal and safest way to use AutoCAD 2009 today is to leverage your or transition to Autodesk's modern subscription-based models , as the company has officially retired the activation servers for this legacy software.
Can´t activate AutoCAD LT 2009 on new computer with Windows 10 autocad 2009 serial number and activation code
If your AutoCAD 2009 is already installed and activated on an old machine, it should continue to function until the hardware or operating system fails. New Installations: The legal and safest way to use AutoCAD