Those downloads and serial numbers were only for use by existing, paying customers that needed to reactivate software that they had already purchased a full, valid license for. What you may be referring to were web pages from a number of years back that provided access to downloads of certain older versions of Adobe applications and replacement serial numbers for same to remedy an issue whereby the activation servers for such versions were no longer accessible.
Let's kill a myth right now! There never, repeat never, repeat yet again never were any “free versions” of Photoshop, Acrobat Pro, Illustrator, etc.
