Take control of multiple Python installations in Windows with the py launcher, available as part of a standard Python installation.

Apart from the step given in the guidelines, I had also added another field GDAL_VERSION with a value of 3.0.4 in the environment variable. Installation of rasterio: I am using Python 3.7.4 (64-bit).

I NEED the 64 bit to be working, and it is not. And sadly, since I run dual-boot with Manjaro Linux 64bit it does NOT have the current release available to install, so right now ONLY hope is Windows.