Since Acrobat 8 is "dead and gone" for activation purposes, you may consider these modern options:
The activation servers for Acrobat 8 and other older versions (like CS3) have been permanently taken offline. Activation Key For Adobe Acrobat 8 Professional
Because the servers are offline, the standard "activate over the internet" feature built into the original software will fail. Since Acrobat 8 is "dead and gone" for
Adobe Acrobat 8 Professional is a powerful tool for creating, editing, and managing PDF documents. It was released in 2006 and offered a range of features, including the ability to create PDFs from various applications, edit and annotate PDFs, and convert PDFs back into editable formats. edit and annotate PDFs