IBM GC23-7753-05 - Manual (Page 19)

User informix
User informix is a user account with main authority over an IBM Informix
instance.
User informix is required for most installations because it has the unique user
identifier (UID) to manage and maintain Informix instances and databases on the
host server. The only exception to this requirement is when you install the
Informix server as local system user.
The password for this user account must be protected. Only let trusted database
and security administrators log in as user informix.
If you are installing Informix for the first time on your system and have not
selected the local system user option, the installation program prompts you to
create the informix user by providing a password. If user informix already exists
on your system, the installation program prompts you to confirm the password.
Important: The database server will not start if password standards for user
informix or any other users do not conform to local security standards.
Other IBM product installation files
The IBM Data Server Driver Package is included in the installation media for
Windows.
When you use the Informix installation application on Windows, you can select to
install the IBM Data Server Driver Package with either IBM Informix Client
Software Development Kit (Client SDK) or IBM Informix Connect. If you select to
install the driver, a separate, short installation application starts. If you do not
install the driver during Informix product installation, you can install the driver
separately later. The IBM Data Server Driver Package directory appears on the top
level of the installation media. For more information about the driver, see the IBM
Informix Client Products Installation Guide
Chapter 1. Preparing to install Informix and client products (Windows) 1-5