You must retarget your projects to Windows 8.1 to open them in Visual Studio 2013 Express for Windows (learn about new Windows ...

You must retarget your projects to Windows 8.1 to open them in Visual Studio 2013 Express for Windows (learn about new Windows 8.1 features). For more information, see how to retarget your Windows 8 app to Windows 8.1.

Clicking OK will leave your Windows 8 projects unloaded.