Hi, Chris_Palmer,
What @albanD wanted to point is to copy the AdamW optimizer since it is just a single PyTorch file.
You can create your own optimizers in PyTorch with no C++ hassle inside.
And the point is you don’t need to migrate to PyTorch 1.3 if you only wanted to use AdamW.
BTW, based on your line:
conda install pytorch torchvision cudatoolkit=10.1 -c pytorch

I installed PyTorch 1.3.0 using Conda on Windows and it just works fine. Thank you so much.