I'm sure that during your startup, some applications are already started that need some components of Visual C++ libraries. Don't know what it could be though.

This is what they say at M$:
For libraries that support side-by-side deployment model (CRT, SCL, ATL, MFC, OpenMP) they are installed into the native assembly cache, also called WinSxS folder, on versions of Windows operating system that support side-by-side assemblies.