How to troubleshoot CreateOUIProcess(): 5 error on Oracle Universal Installer

Hi everyone.

Recently, during a Siebel Web Client install, I faced an odd error when launching Oracle Universal Installer.

The error was: CreateOUIProcess(): 5

After some research, I figured out that this is caused because of my temp folder.

By default, my TEMP environment variable is configured to %USERPROFILE%\AppData\Local\Temp, which was causing the error in the installation.

In my case, I changed this variable to D:\temp and, after that, I was able to lanch the installer as expected.