"Invalid DSN" when trying to install 64 bit vCenter Server

1. You need to download and install the x64 package Microsoft SQL Server Native Client client from Microsoft: http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=536fd7d5-013f-49bc-9fc7-77dede4bb075
2. The ODBC Datasource administrator app must be started from the command line by using the command: %systemdrive%\Windows\SysWoW64\Odbcad32.exe

The DSN needed for this connection is called SQL Native Client (installed in step 1 above). The driver called SQL Server will not work:

        3.   From here on you can follow the official installation guide:  Configure a SQL Server ODBC Connection