In order for the 4D for OCI plug-in to function properly, you first need to install the files (libraries) needed to run the Oracle Call Interface (OCI). 
In just a few simple steps, you can download the Oracle Instant Client and install it.
  - Download the appropriate instantclient-basic-[...] package for your platform here: http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html
 Notes: For 4D for OCI, download instantclient-basic-windows.x64-11.1.0.4.0.zip.
- Unzip the packages into a single directory (e.g., C:\oracle\) and rename the subfolder as "instantclient" to get a path such as: C:\oracle\instantclient
- In the environment variables:
  - Add the ORACLE_HOME variable and set it to the path defined in step 2 (e.g.: C:\oracle\instantclient)
- Edit the PATH variable and add this same path at the beginning
 
- Add a "network" subfolder to this path with an "admin" subfolder (e.g.: C:\oracle\instantclient\network\admin)
- In this "admin" subfolder, create a "tnsnames.ora" file with the parameters to your Oracle server. 
 For example:
 
 XE =
 (DESCRIPTION =
 (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.10.10)(PORT = 1521))
 (CONNECT_DATA =
 (SERVER = DEDICATED)
 (SERVICE_NAME = XE)
 )
 )