There’s no official confirmation, even though Microsoft didn’t call the first major update to Windows 8.1 as Update 1 during the Mobile World Conference last week, but the reliability of sources can’t be questioned.

According to Paul Thurrott, Microsoft will be releasing Windows 8.1 Update 1 at BUILD 2014. More precisely, the update will be available for download on April 2 for MSDN subscribers, followed by a public release on April 8. It also strengthens the spread by Mary Jo Foley of ZDNet.

As we reported earlier, the first major – possibly the only – update for Windows 8.1 will introduce a number of improvements, especially in terms of usability with mouse and keyboard, and non-touch systems.

For non-touch systems, the update includes default boot to desktop; title bar – for modern apps – with minimize and close buttons and snap view options; and the ability to pin modern apps on the taskbar. It will also reduce the occupied space on the disk to make the OS fit for cheaper devices. In an attempt to make the OS more convenient for low-end devices under $250, Microsoft is reportedly reducing Windows 8.1 licensing fee by 70% for OEMs.

The Redmond developers will detail about the update during the annual BUILD developer conference in San Francisco slated for April 2-4. Unlike Windows 8.1, Microsoft will start distributing the update for the general public via Windows Update starting April 8.

On the other hand, April 8 will also be an important day in the history of Windows OS, when Microsoft will finally end the support for Windows XP, and release monthly patches and firmware updates for Surface tablets.

Source: Paul Thurrott on Twitter