Microsoft looked to Bungie's Halo to sell its Xbox console, and it's now planning to see if the same trick will persuade gamers to upgrade to Windows Vista. Yes, Halo 2, which shipped for Xbox over a year ago, is coming to the PC - but you'll need Microsoft's next major operating system release to run it. The game will not run on Windows XP, Bungie admitted this week. It will run "exclusively" on Vista.

Bungie maintains the scheme is "absolutely not" motivated by a desire to drive consumers to Vista, despite going to great lengths in its announcement to stress just how good the new OS will be for them. No, it's all about getting the best quality experience. Which begs the question, if a Pentium III-based PC can deliver said, why not a Windows XP rig?

"Windows Vista will help bring clarity to our customers and help them get more out of their personal computing experience, allowing them to focus on what matters most to them," it says several times in the same announcement. Running Halo 2 on Vista will "ensure the title's uncompromised quality" because the OS provides the "best available technological platform for Windows games".

Beyond that, MS and Bungie aren't saying much. Clearly the PC version won't have Xbox Live support, but it will ship with a map editor. If Halo 2 does multi-player, it won't be cross-platform, Bungie said. As for a system requirement specification, don't ask, they won't tell you. ®