Python source for the Windows (64 bit only!) client launcher and installer.
To get the installer, you can download it here.
If you really want to build the binaries on Windows, you need to have python 3 installed (it helps to add python.exe to your path, which is an option in the installer.) You will also need to use the python 3 branch of pyinstaller. Make sure that the pyinstaller folder is in the same directory as the augur-launcher folder. The last dependency is pywin32. Once you've got all the dependencies, double click build_exes.py and it should build the binaries.
To update the version of geth used in the installer, simply copy the new geth binary into the repo, and run the build script.