First off all, i want to make my point clear. In my opinion if you want to install anything on your windows, you should have the permission. If you just have an user account, some one does not want you to modify the windows (except your user stuff, of course). Why companies dont let the user install all software, i think there is reason...
And this is just my good and bad experience i am talking about.
If you can install anything you want to c:\program files\ with just user privileges, fine, do it. But if it comes to c++ runtimes, please do not just copy anything around. You do not have an overview of all the c++ runtimes your system holds. If you use the installer you can see them in your "Porgrams and Feature" control panel.
Sorry, but please investigate a bit more before shooting around with exclamation marks. Of course one must distribute the DLLs used by the program one compiled with MSVC. This is exactly the same as with the Qt DLLs. It is hereby important to distribute the DLLS of the MSVC and Qt version with which the program was compiled. MSVC and Qt provides really good documentation, so please read it.
This is not my experience with windows software deployment. Qt is deployed by nearly every single program, because their are so many different version out there, even own compiled versions. The problem on windows is, as fare as i know, the dll loading mechanism at runtime. Windows loads a dll with the same name only once. If you just copy your runtime dll to your program and another program installed the runtimes with the installer no one can identify what c++ runtime version is loaded on runtime. I had the problem with own deployed software and bought software. So this is just a hint from my side. And by debuging i did not mean to go through the source code, I meant to check why the program suddenly crashs or dont even start. And all the times it had something with the runtimes...
But again how i started, this is just my opinion and experience with software deployment.
BR Manuel