Hi Francis, this is a bug in version 1803 . . .
Cancel the PIN prompt and login to your PC
Go to Windows Defender Security Centre icon on the tray.
Under 'Account Protection' go to 'Set up Windows Hello for faster, more secure sign-in'
Click 'Set-up', it will prompt you to set up a pin - don't.
Click "Dismiss"
After that, there should be no more prompting at startup
Hello DaveM121,
I have tried this but in my case the PIN request still comes again at the next login. I tried to reconfigure Cortana (I had disabled it while trying to fix this problem!), and also to work via Windows Defender panel, so far no success.
Where I go off track is:
"Click 'Set-up', it will prompt you to set up a pin - don't.
Click "Dismiss" "
There is no dismiss button on the next screen, I can only continue to the enter PIN screen, where I can cancel.
There is a Dismiss displayed under the Defender protection panel, which I have clicked.
The taskbar is showing a Microsoft account program is running when the login is finished (not completed?) which I can close!
So far no way to turn off the PIN request, however there is a bypass of selecting password during login.