How to extract:

The installer, which was created in Inno Setup, tries to install Microsoft Visual C++ Redistributable without asking and even if you already have it.
However, it also executes some needed stuff (e.g. customizing the database).
So download the installer and install it to the default folder. Copy all files to a folder of your choice. Uninstall the application. Launch WinNMP.exe.

If you don’t want it to install MVC, then:

1. Run the installer within a sandbox like in Sandboxie Plus/Classic.
2. Keep clicking Cancel when it tries installing MVC.
3. Move the resulting files to a folder of your choice outside the sandbox.
4. Delete the sandbox.