32 Bit applications like DBM or Admin tool can be started on a 64 Bit OS like Windows 7 or Windows Server 2008 R2.
Such applications are only addressing 32 Bit ODBC connections.
Starting the tool for editing ODBC data sources can be done from 64 Bit or from 32 Bit applications. If you run the ODBC data sources administrator from Control Panel it would only display DSN which were created under 64 Bit.
Starting the ODBC data source administrator out of our Administrator tool will there display the 32 Bit ODBC sources.
This mean that creating data sources from Windows Control Panel does not make them visible in our applications because they will be created for 64 Bit.
This would also fit when you try to import ODBC sources from old 32 Bit Operating Systems to a new 64 Bit one. The 32 Bit OS would store the settings below HKLM \ SOFTWARE \ ODBC \ ODBC.INI. Under 64 Bit this place is used for 64 Bit data sources.
32 Bit data sources are stored on 64 Bit OS below HKLM \ SOFTWARE \ Wow6432Node \ ODBC \ ODBC.INI
Therefore we strongly recommend usage of FileDSN instead of SystemDSN.
Nevertheless it is possible using SystemDSN. We recommend calling the ODBC data source administrator from Admin tool. Please note that you need to execute Admin.exe with Administration rights because normal users do not have write access to management of SystemDSN. 

If you need to run the ODBC Manager for managing 32 Bit database sources while running a 64 Bit Operating System you need to call it manually.
You need to open a Windows Explorer and navigate to C:\Windows\SysWOW64
There you can search for a file called odbcad32.exe and execute it.
Searching for odbcad32.exe form other places will not succeed because this will always call the 64 Bit version.