Hi Axel,
sure I can understand your wish.
rooExtend is basically a cross-platform implementation based on node.js.
The only thing that prevents a Windows release is Bluetooth for rooDial. Bluetooth handling in Linux and Windows is quite different and rooDial is implemented in Linux so far. As both are bundled in the rooExtend platform I cannot offer rooUPnP for Windows now. It would be quite an effort to make rooDial work on Windows.
The current requests regarding Windows are few. This may be caused by the low price and esay setup (important for the customers!) of the Raspberry implementation. So I decided for now to only offer rooExtend for the Pi.
Maybe some day I will spend the effort to port it to Windows but not in the near future. Currently I prefer to offer additional functionality.