Before uninstalling everything I thought I would try to solve it as follows:
I checked my ODBC data source as follows:

Control Panel
Administrative Tools
Data Sources (ODBC)
System DSN tab - I can see Adagio Data Source is linked to Adagio Data Source Driver

If I change to the Drivers tab I can see the Adagio Data Source Driver is version 2.01.08.189 with file ADAGIOODBCV264.DLL dated 2/22/2016

This looks like a 64 bit driver. From an earlier post it appears that I should be using the 32 bit driver ADAGIOODBCV2.DLL
Is this correct, and if so how do I remove the existing driver and install the 32 bit one? The Data Sources (ODBC) help says that I must use an installation program provided by the vendor.