Login failed for user 'sa' while installing SQL Server 2005

I was working in a SQL Server 2005 setup case which failed while starting SQL Service with error: SQL Server Setup could not connect to the database service for server configuration. The error was: [Microsoft][SQL Native Client][SQL Server]Login failed for user 'sa'. Refer to server error logs and setup logs for more information. Then I reviewed the SQL Server error log and noted that DateTime