When there were only two console giants fighting to the death (Sega and Nintendo), Xbox was not even a concept yet. At one point Microsoft considered buying Sega to get into the console market, not really surprising because they already had a following in the console market. Joachim Kempin worked at Microsoft from 1983 to 2003 and reports that Bill Gates did not purchase Sega because he did not think they could not overthrow Sony.

So that is why the Xbox was born. Microsoft licensed a version of Windows to Sega called Windows CE, but that was the extent of their relationship Sega has had some issues in the past few years but they do have some successful PC titles of note. You may have heard of the Total War series. Ultimately the Dreamcast failed and now Sega just publishes games. I wonder what the world would have been like if Microsoft would have purchased Sega, interesting.