(click on the link to see the original flash animated ad). It's not a fake - this ad was indeed published by Microsoft and for a while appeared on Battlestar Galactica's official homepage on Sci-Fi channel.
Related fun fact: Did you know no TV channel carries Battlestar Galactica in Hungary? One of the commercial chanells bought the rights for the first season few years ago, but they stopped broadcasting it after only (I think) six episodes, citing poor viewer ratings. Morons. (Someone was a moron. Either the TV channel producers, or the company measuring the viewership ratings, or, err..., the local TV audience.) If it weren't for BitTorrent, I wouldn't be able to watch it at all. (And I also wouldn't have any motivation to buy the mini series + the first two seasons on DVD + all the soundtrack CDs from Amazon either, which I did recently. So much for studios' fairytale of "lost revenue due to copyright infringement by file-sharing".)