Install OpenCV C++ Visual Studio Windows

 Open installer:

Click Modify.

Add Desktop Development with C++ 

Leave other settings as default and click modify

Download OpenCV from:

https://opencv.org/ 

Go to Library >> Releases and Download OpenCV for windows:

Create a new folder C:\OpenCV-4.5.5

Extract there using the downloaded exe

Setting environment variables:

Add 

C:\OpenCV-4.5.5\opencv\build\x64\vc15\bin

to path

https://en.wikipedia.org/wiki/Microsoft_Visual_Studio#History

Open Visual Studio and create a new project: C++ Console App

Solution platforms must be changed from x86 to x64

Debug for x64

Add OpenCV to libraries:

Change Project Properties - Linking OpenCV

Go to :

1. Configuration Properties/VC++ Directories to add the include and library directories for OpenCV

For the Include directory, you have to add the following path: C:\OpenCV-4.5.5\opencv\build\include. Do the same for the Library Directories adding this internal path: C:\OpenCV-4.5.5\opencv\build\x64\vc15\lib.

2. Edit the VC++ project linker with the opencv_world420d.lib OpenCV dynamic library. You will find the DLL (Dynamic Link Library) here: C:\OpenCV-4.5.5\opencv\build\x64\vc15\lib copy the name of the file opencv_world420d.lib and paste it in the dependency box

A Restart of Visual Studio Fixed the Problem

Optional:
CMake:

https://cmake.org/download/