Unable to connect to the configuration database. Ensure that the database server is online and that the configuration database ...

Unable to connect to the configuration database. Ensure that the database server is online and that the configuration database exists. If the configuration database administration account password recently changed or expired, see the Microsoft SharePoint Server 2010 Administrator's Guide for instructions on how to update the password. If the configuration database or database server is permanently unavailable, click Disconnect from configuration database.