During the install process of Windows 10 Mobile build 10149 something bizarre happened to my Lumia 830. Something I've never seen before on any Windows Phone that's come across my desk.

The BSOD (blue screen of death.) Normally a running joke on PCs, the image up top shows what presented itself when the phone tried to reboot and finish the install. Nothing seemed to work. Not the 'recommended' button press, the reset using the physical buttons on the phone, nothing.

But fortunately there's an easy way out, thanks to the Windows Phone Recovery Tool.

Normally you'd be using this to roll back from Windows 10 Mobile to the safety of Windows Phone 8.1. Fortunately, the same steps can be used here to rescue you from blue screen hell. If your phone is in this state it will keep trying to reboot every minute or so, but that doesn't affect the recovery. Follow these steps to the letter and you'll be OK.

  1. Download and install the latest version of the Windows Phone Recovery Tool to your PC.
  2. Launch the recovery tool and connect your phone using a USB cable. It probably won't detect the phone so click My phone was not detected.
  3. In the next screen, click your phone, wait a few seconds, and you'll see your phone information and the software available for download to roll back to a previous operating system. It'll say something about the phone being in UEFI mode. To continue, click Reinstall software.
  4. Next, the recovery tool will warn you to backup all your data, settings, and apps before continuing, as the rolling back process will delete all the previous data in your phone. Click Continue to proceed.
  5. Now, the recovery tool will download the image from Microsoft's servers and restore your phone to Windows Phone 8.1. It'll take a while, but just leave it alone and let it work its magic.

Once it's done your phone will reboot and you'll be back at the very first step in the Windows Phone 8.1 set up process. Complete all this and you'll be back up and running.

Hopefully this isn't too widespread an issue, but if I've seen it there's going to be someone else who has or is going to. Luckily, Microsoft has all the tools to make it go away with minimal effort.