In this part we will create the DSNs.The three vCenter components which are using databases are Single Sign On, vCenter Server and VMware Update Manager. All those components points to the databases we I have installed on our SQL server 2012 which we have created in this artical http://bzia.blogspot.co.uk/2014/12/installation-of-esxi-server-55-and-its_31.html.
Next step we need to do is to create DSNs. We will use the 64 bit version of DSN and the 32 bit version is still needed for VUM and SRM.
VMware vSphere 5.1 Single Sign-On DB (needs 64 bit ODBC)
VMware vSphere vCenter server DB (needs 64 bit ODBC)
VMware Update Manager DB (needs 32 bit ODBC)
Locate and Open following to setup ODBC data source
Create all three under System DNS
Once the three ODBC connections done, you should see them all in the System DSN tab, and you can start installing the different vCenter components.