WordPress auto-update feature can be useful to keep your website up-to-date, but there can be cases where you might want to install an older version of WordPress and prevent it from automatically updating. Here’s how you can do it:

1. Disable Automatic Updates During Installation:

During the installation process, WordPress does not automatically update. So, you can install an older version without worrying about the update process. However, once installed, WordPress may attempt to update itself. To prevent this, you can disable automatic updates using one of the following methods:

• Using wp-config.php File:

You can add the following line of code to your wp-config.php file. This file is located in the root directory of your WordPress installation.

define( 'WP_AUTO_UPDATE_CORE', false );

This code will disable all automatic WordPress updates.

• Using a Plugin:

There are also several plugins available that can help you manage WordPress updates, such as “Easy Updates Manager”. You can install such a plugin and use it to control the updates as per your requirement.

2. Manual Downgrade After Automatic Update:

If your WordPress has already been updated automatically and you want to revert to an older version, you can manually downgrade it. Here is the general procedure:

• First, backup your WordPress site. This is a critical step because if anything goes wrong, you can revert to this backup.
• Download the older version of WordPress from the WordPress Release Archive.
• Deactivate all of your plugins.
• Go to your website root directory and delete your ‘wp-admin’ and ‘wp-includes’ folders. You can do this via FTP.
• Upload the ‘wp-admin’ and ‘wp-includes’ folders from the old version of WordPress you downloaded earlier.
• Go to your website URL /wp-admin. You may see a message asking you to update your database. Follow the instructions to do so.

Please note that using an older version of WordPress can expose your site to security vulnerabilities and bugs that have been fixed in later versions. Always ensure you understand the risks before proceeding with a downgrade.