At the BUILD developer conference in April 2014, Microsoft will discuss its vision for the future of Windows, including a year-off release codenamed “Threshold” that will most likely be called Windows 9. Here’s what I know about the next major release of Windows.

As a kind of recap, we know that Microsoft will update Windows 8.1 in 2014, first with a service pack/feature pack-type update called Update 1 (or GDR1 internally). I wrote a bit about this update recently in Windows 8.1 Update 1 (Very Early) Preview but the expectation is that it will ship in April 2014 alongside Windows Phone 8.1, the development of which Microsoft will soon complete.