Comment by mitchellh

The various "actions" which build up the behavior of the various Vagrant commands are tightly tied to a unix-based VM at the moment (see [1] for an example at the bottom).

John and I have discussed this and we're trying to figure out a way to pull out this logic so its specific to each box, so windows VMs would be possible.

That being said, assuming a windows VM has SSH, a quick hack would be to modify these actions to run the proper commands and it should work fine.

[1]: http://github.com/mitchellh/vagrant/blob/master/lib/vagrant/...