For vCenter to successfully connect to the SQL database a 64-Bit ODBC driver is required and must be downloaded and installed from the Microsoft website.
1. When using Microsoft SQL 2012 or 2014 as VMware vCenter Server database solution, you must use SQL Native Client version 11 (sqlncli11.dll), available at Microsoft SQL Server 2012 Feature Pack.
See Direct link below
2. On the system DSN tab create a new ODBC Connection by clicking add and selecting SQL Server Native Client 11.0
3. The wizard will help you create an ODBC data source that you can use to connect to SQL Server
Name: VCDB , which is the default name of the vCenter Database
Description: vCenter Database
Server: <Database>\<Instance>, type in the SQL server name if not in the drop down menu
4. Select authentication Method, with SQL Server authentication using a login ID and password entered by the user. Type your SQL Login ID and Password.
** Below is the default Login ID and Password created by the vCenter SQL scripts
Login ID: vpxuser
Password: vpxuser
5. Select the database created for the vCenter Server from the Change the default database to menu
6. Click Finish
7. Test Data Source and click ok from the SQL ODBC Data Source Test