To install the Oracle ODBC Driver:double-click odbc_install.exe in your Oracle Client folder (eg. d:\Oracle_Client)
Note that this will not actually install any software - what it has done it to register the Oracle ODBC Driver (SQORA32.DLL) to the Microsoft ODBC Driver Manager.
To see whether this has installed, go to the AQT Signon window and click on Add new Datasource. If the ODBC Driver has installed correctly, you will see it in the list. .
You cannot create a datasource yet until you have done some other steps.