David Plummer, the ex-Microsoft engineer who served as the primary author for Windows XP's Product Activation system on the OS side, has shed light on the origins of the notorious 'FCKGW' product key. This key became ubiquitous on pirated, home-burned CD copies of the operating system.
"As you likely recall, Product Activation required that you have a key, and you’d have to activate it online or over the phone," Plummer explained. However, Microsoft recognized that large corporate customers would not want to activate every offline PC. These customers received a Volume Media disc image, which was unlocked by a Volume Key. To verify the legitimacy of such installations, the product activation system checked the disc image for a secret 10 MB "binary blob," present only on the Volume Media. This data blob was, in fact, an encrypted version of Microsoft Bob.
Plummer elaborated that he compressed and encrypted this data multiple times, stating, "Rest assured it’s encrypted and even in the AI age no one has extracted it yet." He used this precompressed binary image as random data, admitting, "I was young and didn’t know if I could trust CryptGenRand."
Consequently, using the 'FCKGW' key on a standard XP CD would not work because the "Bob in your bits" check would fail. However, if one possessed the Volume Media disc and a copy of the key, a seemingly legitimate Windows XP installation could be achieved. The situation was exacerbated when a piracy group known as Devils0wn released a complete Windows XP Pro Corporate ISO, along with the valid 'FCKGW' key, mere weeks before the official launch. Since Windows Product Activation would skip further validation if a mathematically valid key was combined with the Volume Media data check, this effectively created legitimate-seeming installs.
"Pirates then started baking the key into images or just writing it on the CD with a Sharpie," Plummer noted. He speculates that the key likely originated from an OEM or hardware partner that received final media early to prepare for PCs shipping on launch day. While names like Dell and Intel have been mentioned, Plummer acknowledged that he does not know the exact source, stating, "Presumably someone does."
In response, Microsoft began blacklisting product IDs associated with the leaked keys in Service Pack 1. Service Pack 2 further escalated this by making the check more aggressive and blocking updates for installations using the compromised key. However, Plummer confirmed that authentic, un-leaked Volume License Keys continued to function with Volume Media versions of XP for years.
"The operational failure was that the media and one of those keys left the building before the product even reached stores," Plummer concluded. "Once both pieces were public, WPA’s hardware-binding never got a chance to run."
Interestingly, Plummer mentioned in comments that he never encountered a key generator that actually worked for Windows XP. Other users in the discussion speculated that available key generators at the time likely just randomly selected leaked Volume Media keys from a list rather than truly generating them.