Setup Oracle 32-bit client and 64-bit client on a workstation

Sometimes it is necessary to have both a 32-bit Oracle client as a 64-bit Oracle client on the same system. This is for example the case if you develop for various PeopleSoft systems that run on different PeopleTools versions. For example if you have a system on PeopleTools 8.52, which provides 32-bit versions of applications like Application Designer and Data Mover, you will need a 32-bit Oracle client. Since PeopleTools 8.54 these applications are 64-bit and then you need a 64-bit client.
Another situation can be when you upgrade PeopleSoft from 9.1 to 9.2 for example and you go from a 32-bit PeopleTools version to a 64-bit PeopleTools version. In this case Change Assistant will require access to different tools versions which require different Oracle clients.

This article describes how to install both the 32-bit and the 64-bit Oracle InstantClient on a workstation.

Step 1: Install Oracle 32-bit and 64-bit InstantClients

Go to the Oracle website and download the two versions of the InstantClient marked as:

  • Instant Client for Microsoft Windows (32-bit)
  • Instant Client for Microsoft Windows (x64)

For both download the Basic and the SQL*Plus packages.


Create a folder structure like this:
C:\Oracle_Client \12c_64
Extract the 32-bit Basic and SQL*Plus package in C:\Oracle_Client\12c_32.
Extract the 64-bit Basic and SQL*Plus package in C:\Oracle_Client\12c_64.

Note: Oracle InstantClient is enough to be able to connect with PeopleTools to a database. Using the full Oracle Client software is also possible of course.

Step 2: Make soft links

Next step is to make two soft links. We need to make a soft link in C:\Windows\System32 and one in C:\Windows\SysWOW64. The one in System32 points to the 64-bit binaries and the one in SysWOW64 points to the 32-bit binaries. Start a command prompt in administrator mode. To do this do the following:

  1. Create a shortcut to CMD on your desktop
  2. Right click on it and go to properties. On the shortcut tab choose advanced and select run as administrator

Now start the command prompt with the shortcut and do the following to create the soft links. We use the mklink command to create the soft links:

cd \Windows\System32
mklink /D oraclient12c C:\Oracle_Client\12c_64\instantclient_12_1
cd \Windows\SysWOW64
mklink /D oraclient12c C:\Oracle_Client\12c_32\instantclient_12_1

The syntax for the mklink command is as follows. The parameter D is used to indicate that we link to a folder and not to a file: mklink /D [name of the link] [folder to link to]

Step 3: Change PATH variable

Last thing to do is to change the PATH variable. Go to System Properties and there, on the Advanced tab, go to Environment Variables. Change the PATH variable under System variables.


Remove all existing references to Oracle Client software and add the following location to your path: c:\windows\system32\oraclient12c


Step 4: Result

Now you should be able to log into PeopleSoft enviroments using PeopleTools 8.53 (or lower) using the 32-bit Oracle InstantClient. You will also be able to log into PeopleSoft environments with PeopleTools 8.54 (or higher) using the 64-bit Oracle InstantClient.

As Change Assistant uses both 8.53 and 8.54 in the patching process if you are updating a 8.53 environment with a 8.54 based PUM image, this setup is mandatory.

The method used here is based on using a File System Redirector. This method is described here:

2 thoughts on “Setup Oracle 32-bit client and 64-bit client on a workstation”

Leave a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.