I have just purchased a bluetooth dongle for my desktop PC, Windows 7. I inserted the dongle in a spare usb port. My PC recognises the dongle and shows it is connected to my Samsung Galaxy j3 (2016), and my Hudl 2 android tablet. My phone and tablet are both showing connected to User PC. I have managed to send a file from my PC to phone. When I try to send a file from phone to PC, it says "Sending file", and then says "File not sent".