Yesterday's launch of Windows Vista marked the culmination of the months-long puzzle adventure known as Vanishing Point, a globe-spanning alternate reality game engineered by Microsoft and interactive agency 42 Entertainment to drum up support for the much-hyped operating system among the influential technology blogger community. "In its design, Vanishing Point is definitely an ARG," says Brian Marr, group marketing manager for Windows Vista. "However, by combining it with puzzle elements that anyone could get involved with, I feel like we transcended the ARG genre and created the world's largest puzzle."

Starting with references to the Bellagio Hotel fountains and a character named Loki in Bill Gates' Consumer Electronics Show speech earlier this month, players gathered in forums and wikis to collectively tackle a series of puzzles unveiled at VanishingPointGame.com. With clues scattered across the web and in real-life locations around the world, the quest to solve the puzzles took on a truly global scope—and the process of creating the experience was just as epic. "The creative process started with the overall idea of Loki the Puzzlemaster, with the online and offline elements as a framework, and it took off from there," says Marr. "Themes were created for each week, and the meta-puzzle about Loki took shape during the weeks and months of planning that followed original concept approval. And we really have to give 100% credit to 42 Entertainment for the puzzle creation. Only the really hardcore players caught onto this, but Loki actually has a physical office on the Microsoft campus, and a phone you can call. The depth of the thinking was incredible!"

Microsoft also demonstrated a keen understanding of their core demographic, as online word-of-mouth has contributed greatly to the viral spread of the campaign. "Reaching out to the blogging and technical community was the primary intent of this program," says Marr. "We wanted to create something special and entertaining for them with no explicit marketing to thank them for their involvement with Windows and Microsoft. We've spent a huge amount of time following their reaction and comments. It's been overwhelmingly positive, which is exciting to see."