Deploy OJDBC and Environment Variables

BenS

We currently have a full suite of Oracle products: Siebel, OBIEE 12c, NetSuite, PS FIN and HR, Databases, Informatica, SQLDeveloper, etc..

I've created an a folder on my C: drive called Oracle and installed in that folder the following:

1. c:\Oracle\InstantClient_12_2
2. c:\Oracle\Middleware\OBI12C12.2.1.1
3. c:\Oracle\Middleware\ODAC121024

In c:\ProgramFiles\Java I have the following Java folders:

1. jdk1.8.0_231
2. jre1.8.0_231

In c:\ProgramFiles(x86)\Oracle Developer Tools for VS2017

We are running Oracle database is 11 (to be compatible with our Siebel and Informatica ETL processes). 

Here is my confusion:  When I try to connect to the Oracle databases using various tools:   Microsoft Power BI, Data Virtuality, Google Data Fusion, Squierl, etc... I get mixed results and messages.  Some saying that I DO NOT have an ODBC driver installed or No suitable driver found for jdbc:oracle:oci8 or OCIJDBC12 is nout found on the path.  .

I'm including the list of environment variables as I currently have them set.  What I struggle with is understanding which ones should be on the path (they seem to have overlapping jar files but no consistency).  The instant client has the ojdbc8.jar and the ocijdbc12.dll  but no JDBC folders and files.  The ODAC has the ojdbc7.jar in the \jdbc\lib folder with no other files and the \JDK folder with the jre, bin and lib folders beneath. 

My assumption, is that it is a matter of putting the OJDBC amd JDBC drivers in the correct path in my environment variables or that there is an install files to be executed.  I have not found a clear explanation of how to set these up and also verifying versions or deployments through a command prompt.  Please advise as to the correct environment variable setup and verification?

Thank you...

Here are my environment variables:

System Variable Path:

System variable JAVA_HOME:

System variable ORACLE_HOME

System variable TNS_ADMIN