The only actively supported operating systems at this time are most Linux distros and OS X.
You can use pip:
$ pip install fastecdsa or clone the repo and use
$ python setup.py install. Note that you need to have a C compiler (you can check this via
$ which gcc or
$ which clang). You also need to have GMP on your system
as the underlying C code in this package includes the
gmp.h header (and links against gmp