Users often turn to keygens to generate "authorization codes" that trick the software into thinking it has been validated. Official Workaround (Historical):

For several years, Adobe provided a specific installer and a universal serial number that did not require online activation for registered users. However, Adobe stopped providing these downloads entirely in 2. Critical Risks of Using Keygens

Using keygens to activate legacy software like Acrobat 7.0 carries significant legal and security dangers. Adobe Acrobat 7 Professional | Adobe Wiki | Fandom