I think Matt Harbison takes care of Windows builds. They are bundled with the official TortoiseHg download:

https://tortoisehg.bitbucket.io/download/

I did not use them because I am on linux only, but I see that Matt is active and responsive, both on the mailing list and chasing bugs on the issue tracker on heptapod ( https://foss.heptapod.net/mercurial/tortoisehg/thg )