I tried to install the Windows 10 preview on my lumia 520 but after the spinning gears it always gave back an error code when it rebooted into windows 8.1. I decided to try and reset to fix the problem. It failed after 5 minutes and gave back a sad face and does this each time I reboot. I have tried many of the fixes on the site but I cant get the phone into any other mode other than the spinning gears and sad face. It connects to the computer for a few seconds that says Nokia Bootmgr in device manager but then just disconnects. Pressing the volume down doesnt work. Any suggestions?