@fabpot @vicb I dont think it's important,
* `return true` means each tested command is available on windows plateformes,
* `return false` means no tested command is available on windows plateformes.

Considering that  Windows plateformes support is not implemented and that none of the two solutions would be acceptable, I guess the only important thing is to return a boolean, whatever its value.

That said, `false` may be safer than `true`.