Why is not Windows Universal Runtime needed on Win 7?

Trying to get my app over to 2016r1 and the new requirements.
Right off the bat I have to say that running an installer is not possible, the vast majority of our users are inside of schools or organizations where they don’t have admin rights or privileges to make system modifications. To handle this we have for the last 10 years distributed the application as a zip-file and hope to be able to continue doing this.

I have just done some initial testing on Windows 7 64-bit and I am a bit confused. The system does not list the 2015 version of C++ redistributabels in the Control Panel installed Programs and I have not included the 41 dlls in the app directory. BUT still the app runs perfectly fine?!? Does this mean I am not using any new functions requiring the C++ redistributabels? Versions 2012 and 2013 are installed on the system - is there any fallback mechanism?

It is my intention to include the dlls alongside the EXE but I wanted to see any possible error messages that our users may see, that’s why I am testing.

Microsoft considers the Universal C Runtime as part of Windows now, and distributes it automatically via Windows Update. That is likely why your app just works on that installation.

Ok. So a working application means that the system is OK even though the 2015 C++ isn’t listed. It is there “somewhere”?

Correct. The Visual C++ 2015 runtime is one way of installing the Universal C Runtime- it isn’t the only way. Windows Update also installs it. It can be dependent on your exact OS/update path, but KB2999226 is an example of a Windows Update that installs it.

Good. Then I know a bit more to be able to troubleshoot of needed. Some schools are really conservative when it comes to patching. They prefer complete reimaging at logout to have a stable environment during the semesters.