If you are running SharePoint 2013 in Windows 2012 then Windows 2012 will force the administrator password to be expired (which I feel this is no right). You SharePoint2013 will get you “HTTP Error 503. The service is unavailable” when you want to navigate to SharePoint 2013 Central Administration.
The only way I make it work is
1. Disable all the Group Policy for Password.
2. Disable all the Local Security Policy for Password.
3. Set the administrator password back to original.
Let me know if you find a better way to make it work.