As a note, the artifacts that you're seeing on the Mac are due to GPU Preview, which can cause issues with fine lines.
If you press CMD + E you can switch between CPU and GPU preview.
You'll see the issue go away on CPU preview.
The Windows machine may not have a compatible GPU to support GPU acceleration, so it will always display in CPU preview.
In any event, this is a display artifact only, will not show if exported, even in raster format.