VMware vCenter Error: Database connection has failed.

I got an error "Database connection has failed" during vCenter 5.1 SSO. 
The error message was: 


VMware vCenter Sing Sign On service keeps data into a relational database. I installed MS SQL Server 2008 R2 express, which is provided as bundle database of vCenter. (It additionally needs to install SQL Server Management Studio GUI console)

After I was checking %temp%\vm-sso.javaLib.log, logs were follows: 

[2013-01-15 19:17:06,599] INFO ... - IP stack is fine

[2013-01-15 19:17:06,599] INFO ... - IP Stack works

[2013-01-15 19:18:46,392] INFO ... - Validate database connection

[2013-01-15 19:18:46,392] INFO ... - DB information jdbcUrl:jdbc:sqlserver://;serverName=vcenter;port=1433;databaseName=RSA type: Mssql
[2013-01-15 19:18:46,392] INFO ... - Initialize values of user DBA user RSA_DBA , other user RSA_USER
[2013-01-15 19:18:46,392] INFO ... - DB information jdbcUrl:jdbc:sqlserver://;serverName=vcenter;port=1433;databaseName=RSA type: Mssql userName:RSA_DBA
[2013-01-15 19:19:16,621]ERROR .... - Failed to established connection :com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection to the host vcenter, port 1433 has failed. Error: "Connection refused: connect. Verify the connection properties, check that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port, and that no firewall is blocking TCP connections to the port."
[2013-01-15 19:19:16,621] INFO .... - could not close JDBC connection

The resolution was simpler than I expended. I found the answer from this site: http://vhomelab.com/2012/09/21/vmware-single-signon-service-inventory-service-vcenter-5-1-installation/

This post of the site has been well written about every step of installation of vCenter 5.1.  

Go to the manu "Microsoft SQL Server 2008 R2 > Configuration tools > SQL Configuration Manager" and should configure to set TCP Port property to 1433

Before I found the site which gave me an resolution, I re-installed SQL server , and then created DB and users manually, however you won't need to do these useless tasks if you already set tcp port.