This is a very useful command to remove any Security Policies that have been applied to a computer previously on a domain.
When removing a computer from a domain, there can be various settings that get left behind (password complexity requirements, User Rights Assignments etc).
To remove any left over Security Policies on a PC, open a command prompt and run the following command:
secedit /configure /cfg %windir%\repair\secsetup.inf /db secsetup.sdb /verbose
secedit /configure /cfg %windir%\inf\defltbase.inf /db defltbase.sdb /verbose
This will take a few minutes to reset all the policies back to the Windows defaults.
Restart the Computer.