Sorry Only just saw this, I tried with a number of Class 10 cards (Adafruit sell a Window IoT kit which includes a Class 10 card) From a couple of manufactures.

Sorry Only just saw this, I tried with a number of Class 10 cards (Adafruit sell a Window IoT kit which includes a Class 10 card) From a couple of manufactures. All of them would take the image just not boot the image. I was never too bother to check if their was any error messages thrown out over serial. It was just a pasing interest and I couldn't be arsed enough to get another SD card on MS's tested list to try again.