I have Win10 running on 820, no problems. Tried to move an app to SD card, got the response "This drive had apps from another device. To use this drive, the other apps must first be deleted. Do you want to continue?" If I the look at what is stored on the SD card, it shows under Apps & games a long green line with 170GB used, which is crazy. The only other stuff on the SD card is 10MB of photos - about 6 in all. Shows 0 bytes for Maps. One map (South Africa) is stored in memory and is 278 Mb is size. I tried to move this to SD, but it only offered to delete. not move. Any ideas?