Are you able to Use FaceTime?
pple has indicated previously that it means to make FaceTime an open standard, meaning that anyone would be able to create software that operates with FaceTime. This would throw open the doors to third-party programmers creating all types of FaceTime-compatible programs, including those who run on Windows (and, presumably, other platforms, like Android). But this hasn't happened yet (no word on the cause of the delay) so much talk of that standard recently may not be coming, and there hasn't been it.
This indicates that, at least for the time being, there's no means for someone using Windows to make a FaceTime call to someone using, for example, a iOS apparatus via the FaceTime app (or for someone on a iOS apparatus to call into a Windows user via FaceTime). I'll update this page if and when that changes.
http://www.techirs.com/2014/06/08/facetime-for-pc/
