There is no Windows 8 SDK in the latest Visual Studio setup. Just the 10 one. And it’s installed.
Still doubt it’s related. The Entry Point in DLL is a hook for Windows Store.
Are you still experiencing these issues? Was it an SDK problem? Not even cooked Windows 7 builds works anymore on a fully patched machine with UE4 Redist installed
Basically, in 4.25 Epic (presumably by accident) started using the CreateDXGIFactory2 API (along with other DXGI functionality) that is only available in Windows 8.1 and newer. From what I understand, the issue has been reverted in the git repository on June 2nd but they appear to wait releasing the fix.
If you need Windows 7 support right now either:
Stick with 4.24 until 4.25.2 (not sure if it comes/fixes the issue) or 4.26 comes out.