Error in installing Matplotlib : fatal error C1083

After spending a lot of time on the issue, this helped me to solve it:

python -m pip install -U matplotlib==3.2.0rc1

You have python 3.8, not python 3.7.
But there are no python 3.8 wheels available for matplotlib 3.1.1 on pypi. So best remove python 3.8 completely and install python 3.7.
When you then run python -m pip install matplotlib it will install the compiled version from the wheels, so there is no need to compile anything yourself or have Microsoft Studio available.