How to Remove ODBC Data Source if Driver is Removed

They are defined in the registry under \ODBC\ODBC.INI\ in various places depending on if the definition is

System User:

HKEY_CURRENT_USER\Software\ODBC\ODBC.INI

32-bit:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ODBC\ODBC.INI

64-bit:

HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI

To delete a data source, you have to delete the data source key under ODBC.INI and the entry under ODBC.INI\ODBC Data Sources linking your data source to the driver.

I had same issue here. But I found my 32 bit entries under:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ODBC\ODBCINST.INI