You should be installing the 32 bit client if you are trying to connect from Desktop. If you are trying to connect from Pro or Server you need the 64-bit client. I usually install the Oracle full client and run the installer with the default settings.
Instant Client downloads for Windows - 32 bit client download of the instant client.
From Oracle Site:
The general steps to install Instant Client are:
1. Download the appropriate Instant Client packages for your platform. All installations require the Basic or Basic Lite package.
2. Unzip the packages into a single directory such as "instantclient_12_1".
3. Set your environment's library loading path (for example LD_LIBRARY_PATH on Linux, or PATH on Windows) to the directory created in Step 2.
4. Start your application.
Refer to any detailed instructions on the download page of your platform for more information.
***Update - Best to match the instant client to the exact version of Oracle that you are connecting to.
--- George T.