When you make changes in Admin Tools / ODBC, the changes go into the
Registry (unless you make a File DSN, but that's another story - actually -
that's real handy too because it shows you the settings in a text file
format for a certain connection).



For User DSN's check out HKCU\Software\ODBC\ODBC.INI.

For System DSN's, check out HKLM\Software\ODBC\ODBC.INI