To install Rasterio on a Windows machine, you need to download the rasterio and GDAL binaries for your system and run:

>> pip install -U pip
>> pip install GDAL-1.11.2-cp27-none-win32.whl
>> pip install rasterio-0.24.0-cp27-none-win32.whl

Using conda, you can install rasterio this way:

>> conda config --add channels conda-forge # this enables the conda-forge channel
>> conda install rasterio

conda-forge is an additional channel from which packages may be installed.

Detailed installation instructions for different platforms are available here: https://mapbox.github.io/rasterio/installation.html