is it there any need to start an separate site for microsoft?
For my money, it's the same need for there to be a site for Apple. For Unix/Linux. For Ubuntu. For Android. And the only reason we don't have one for Microsoft is because doing so would leave SuperUser a ghost town.
Every other major OS vendor gets a site for their stuff and their ecosystem of applications. But not Microsoft. They have to share it with the "generic" heading, which at this point really just means "Microsoft and the maybe 2% of other things that don't get their own websites."
It's like Microsoft lost a really stupid game of musical chairs, so now they're stuck in generic-land. And because of the asinine rule of SU that smart-phones don't count (a rule that gets stupider every year. Even moreso now that tablets are allowed, but a slightly smaller device that uses the same OS and runs the same programs doesn't count), it leaves mobile Microsoft OS stuff in limbo.