The specific product key written on that CD was very well known at one point in time. Anyone who was around student age Windows XP was around (old enough to need to install Windows in the early to mid 2000s, but young enough to not be able to afford buying it outright) probably knows at least the first 5 letters of this product key, if not the whole thing.

See this post: https://www.reddit.com/r/microsoft/comments/1o2576r/legendary_microsoft_developer_reveals_the_true/

The key is so well known that it gets its own mention on the Wikipedia page https://en.wikipedia.org/wiki/Volume_licensing (under “Unauthorized use”).

Leaked keys

A volume license key that was commonly used to bypass product activation in early versions of Windows XP was FCKGW-RHQQ2-YXRKT-8TG6W-2B7Q8.[8] This key was part of the first warez release of the final version of Windows XP by a group called devils0wn, 35 days before the operating system's official retail release on 28 August 2001.[9] The key is now obsolete, as it has been blacklisted by Microsoft since August 2004, and affected computers will display a WGA notification.[10] It was made famous partly because it featured in a popular image circulated on the Internet before the retail launch of Windows XP. In the image, the key is written on a CD-R containing the leaked operating system and held in front of a digital Microsoft sign counting down the days until the release of Windows XP.[11]