The latest windows iot build from October 2015 has the onboard serial pins enabled now. You can also go from USb to Usb in some cases with no adapters needed. I have it semi working with a few issues. You can check out this thread [here][1], if you want to take a look at the issues im running into


  [1]: http://stackoverflow.com/questions/33339074/windows-10-iot-serial-working-on-rp2-but-read-serial-data-incomplete