We have experimented with a Windows port using MinGW/MSYS, but have no plans to invest in this port right now. Due to its Unix heritage, porting Bazel is significant work. For example, Bazel uses symlinks extensively, which has varying levels of support across Windows versions."

In other words: it's a lot of work, and frankly, our team doesn't know enough about windows to be very good at porting it. We would welcome contributions to make it work on Windows, of course.