Ex-MS engineer reveals the story behind the infamous 'FCKGW' Windows XP key: 'Pirates started baking the key into images or just writing it on the CD with a Sharpie'

Former Microsoft engineer David Plummer has shed light on the origins of the infamous Windows XP FCKGW product key, which was widely used on pirated, home-burnt CDs in the early 2000s. Plummer, who was the primary author of Windows XP's Product Activation system, explains that the key was first leaked by a major OEM or similar company with early access to Microsoft's then-new, all-blue XP operating system.

The Product Activation system required users to have a valid key and activate it online or over the phone. However, large corporate customers wanted to avoid activating every offline PC, leading Microsoft to provide Volume Media disc images that could be unlocked with a Volume Key. Plummer suggests that the encrypted 10 MB binary blob found in the disc data was Microsoft Bob, a fun aside within the activation process.

To create a valid FCKGW key, Plummer compressed and encrypted the Volume Media data several times, eventually arriving at the key FCKGW-RHQQ2-YXRKT-8TG6W-2B7Q8. He discovered that if users had the key and a copy of a disc from the leaked ISO, they could bypass the activation process and install Windows XP legitimately. Pirates then began baking the key into images or writing it on CDs with a Sharpie, leading to widespread piracy of Windows XP.