ok, if you make the following modification to your registry the option will be available again in netplwiz. Default setting is 2.
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\PasswordLess\Device] "DevicePasswordLessBuildVersion"=dword:00000000
0 = on
2 = off
It was because my VM was part of a domain (an organization in Windows 10 parlance). Removing the machine from the domain (“disconnecting from the organization”) made the checkbox reappear and allowed me to enable auto-login.
You can use Autologon.exe (Sysinternals tool) or using registry keys:
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon] "AutoAdminLogon"="1" "DefaultDomainName"="DOMAINNAME" "DefaultUserName"="USERNAME" "DefaultPassword"="PASSWORD"
MS removed this option in one of their latest builds (2004 I think). It seems based on my research if you have done clean an install with a new ISO it will not display this option. However if you did an upgrade it you will still have this option.