Windows Server 2008 x64 and Windows 7 x64 have both 32 bit ODBC data sources and 64 bit ODBC data sources. They are managed separately.
Setting up a 32 bit ODBC connection in Windows Server 2008 x64. Start, Run, C:\Windows\SysWOW64\odbcad32.exe (and best create a shortcut to this).
To setup the 64 bit ODBC connection go to: Control Panel, Administrative Tools, Data Sources (ODBC).
For consistency you should setup a matching 32 and 64 bit connections. Otherwise you may run into the error "[Microsoft][ODBC Driver Manager] Data source name not found".