Its essentially XP Pro but has advanced features for media feed back. It actually is very interesting. Currently I have an XBOX360 (I'm an MS fan boy) and I'm able to stream video, music, and pictures from my pc to my 360. I can also record live tv and store it to my HDD. If your in to all that tech stuff and want the "entertainment experience of the future" then its a good investment, or you may just want to wait till the end of the year when Win Vista is launched (suppose to contain media center).