Microsoft released the latest build of Games for Windows - Live.
Games for Windows Live 3.0 Released : Read more
Games for Windows Live 3.0 Released : Read more
GameGuard has nothing to do with MS and everything to do with Sega's choice. its was on the other Phantasy Star games as well. Many MMOs from countries on that side of the world use GG.If it's the same as Phantasy Star Universe, you'll have the game guard going online, checking/verifying your version, and enabling multiplayer access.
For single player story level, you still have to go online for the verification.
So I guess this is about the same...