Let it keep running. There have been instances on the forum where it took hours and then successfully completed. If you grow impatient and restart the system it may brick the MB.

Hi,

How many times have flashed before Dell BIOS?

What is the current BIOS version and what new version you are trying to install?

Have you ready any previous emails on this forum about the same problem?

I my case the power button did not work. But I was stuck to 0%. Do never remove the battery!

I removed the power core so systems run out of juice and I could restart the PC.

But before you loose nerve, wait at least total 1h. If not done. Something may have be done.

You can't wait forever.

I hope you have disconnected all your external devices before BIOS update.

Especially the Dell WD19DC dock.

Please reply how did manage to resolve the case. Rest of us may learn something.

I read previous messages. The machine was unresponsive, the power button didn't work.

I decided to risk it and removed the battery to power down. Then powered up again, and there was an automatic re-installation of the so called "corrupted" bios. 

Finally, the machine booted windows 10 correctly. 

My wild guess is that the thing was stuck at 100% because I had forgotten to unplug a USB hard disk.

Today the old BIOS version 1.10.2 is not anymore available to be downloaded. But for example the notorious BIOS version 1.13.1 is still available. This will stuck 0% if Dell WD19DC is connected.

Today the latest BIOS version is 1.15.1.