I have a directory "C:\Program Files (x86)\Windows Kits". An exe in the subfolder of this folder is being called when I build a winPhone App. I did not install this specifically. How was this installed on my system? I am guessing maybe it came with windows install or some visual studio install. How do I update this? I have 8.0, 8.1 and 10 as subfolders too. I think I can manually update each version from here. https://developer.microsoft.com/en-us/windows/downloads/sdk-archive
Just trying to figure out how these are installed and how are they supposed to be upgraded.
Windows Kits are available in stand-alone downloads, but primarily they are deployed and upgraded by Visual Studio.
Visual Studio 2013 includes Windows 8.1 SDK (for Windows Store apps and Windows desktop apps on Windows Vista SP2 or later) and the Windows 7.1A SDK (for Windows desktop apps on Windows Server 2003 SP1 or Windows XP SP3). VS 2013 Update 5 included the Windows 8.1 SDK (Spring 2015 Refresh).
Visual Studio 2015 includes the Windows 8.1 SDK (Spring 2015 Refresh) and Windows 7.1A SDK by default, and installing the Windows Tools option for UWP development adds a Windows 10 SDK. There are currently three versions available: 10240 (RTM), 10586 (Version 1511), and the latest is 14393 (Version 1610). A little bit of the Windows 10 SDK is always installed to support the Universal CRT used by Visual Studio 2015.
Windows 10 SDK versions are side-by-side installed.
See A Brief History of Windows SDKs.
For more on using the Windows 7.1A SDK for targeting Windows XP SP3, see Visual Studio 2012 Update 1
UPDATE: VS 2017 initially shipped with Windows 10 SDK (14393). Later updates included 15063, 16299, 17134, and 17763. VS 2019 shipped with Windows 10 SDK (17763) but was updated to include 18362 and 19041.
VS 2015 is only officially supported up to Windows 10 SDK (14393). VS 2017 can use Windows 10 SDK (18362) or Windows 10 SDK (19041), but you have to install it separately from VS 2017.