Windows XP activation: game over
In a post last year on the Windows XP subreddit (Windows XP web activation is finally dead...), retroreviewyt shared xp_activate32.exe4, which calculates the Installation ID then generates and optionally applies the corresponding Confirmation ID to activate Windows XP, all offline. Wiping the system and reinstalling Windows XP results in the same Installation ID being assigned by Windows (assuming no change in hardware or product key), thus the same Confirmation ID obtains even in msoobe's standard telephone activation window.
Long considered out of reach, this development bodes well for salvaging old systems even after Microsoft has shut down the activation servers.
Incredible team effort spanning several decades. That being said, it's quite sad that we do not live in a world where Microsoft just releases a simple tool to allow anyone to install XP anywhere without the need for activation.