That special moment has come which usually rolls around only once every three years: Microsoft has released a new version of Windows. For the version 8 update, though, the stakes are higher than ever. Redmond isn't just trying to convince legions of existing Windows users that they should break their PC update cycles. It's trying to reclaim a foothold in a tablet space that's now dominated by Apple and Google -- and it's dipping into self-designed computers for the first time with a Surface tablet
