[Neehad Islam]

I chose the "fast" ring update on the windows insider app in order to get the preview for windows 10 on my lumia 1520. It updated fine but since the migrating data process began, it has been stuck in a continuous reboot loop. The screen shows the nokia logo and the windows logo briefly, then shows the at&t logo (since I bought the phone in the US) with "not for resale" written in the bottom left corner. How can I fix this? I don't mind losing all my data.

[Sebastianx]

I chose the "fast" ring update on the windows insider app in order to get the preview for windows 10 on my lumia 1520. It updated fine but since the migrating data process began, it has been stuck in a continuous reboot loop. The screen shows the nokia logo and the windows logo briefly, then shows the at&t logo (since I bought the phone in the US) with "not for resale" written in the bottom left corner. How can I fix this? I don't mind losing all my data.

Try to reset the phone using buttons. Seems like you didn't finished the migration status it was noted that you need to wait for more than 10 minutes and wait for the clock to appear. If you haven't and you restarted / reboot your phone then you end up in a funky state.

[sandsedge]

I was in the same boat. Tried multiple times to install Win 10 Preview 3 days ago on Fast Ring. It failed, and I retried a few times, and it would always get an error, but the phone was still working. I attempted a total reset and it got stuck in the reboot loop. The hardware reset button combination didn't work.

I discovered the Lumia Software Recovery Tool, and after a few "hold the power and volume rocker down" restarts, the software was able to reset my 521 to working order!

[Rainmarie]

I had the same issue. Doing a hard reset made me think I bricked my phone because kept getting a sad face. Finally the recovery phone restored my 1520 and build 10149 is smooth but I have to keep it charged while on the internet or it will shut off.