One Web site claims the spring update to Windows 8.1 won't just be a traditional service pack.
An update to Windows 8.1 reportedly planned for the spring is now showing off online via a series of leaked screenshots.
Served up by Russian Web site Wzor, the images show the same internal version number currently found in Windows 8.1 Pro (version 6.3.9600) but the full build number is intentionally blanked out. Assuming the images are accurate, that means the update won't carry with it Windows 8.2. But it won't be a simple service pack or collection of security updates, at least according to Wzor.
Source: Windows 8.1 update images pop up online | Microsoft - CNET News