Installing WHMCS in cPanel & WHM involves a series of steps, including uploading files, creating a database, and configuring settings. Here's a step-by-step guide:

1. Login to cPanel & WHM:

   • Access your cPanel & WHM account using your credentials.

2. Upload WHMCS Files:

   • Navigate to the "File Manager" in cPanel.
   • Create a directory where you want to install WHMCS (e.g., public_html/whmcs).
   • Upload the WHMCS files you downloaded earlier into this directory.

3. Create a Database:

   • Go back to the cPanel home and find the "MySQL Databases" option.
   • Create a new database and a user with privileges for that database. Make note of the database name, username, and password.

4. Assign User to Database:

   • In the "MySQL Databases" section, scroll down to the "Add User to Database" section.
   • Select the user and the database you just created. Click "Add".

5. Configure File Permissions:

   • Ensure that the files and directories in your WHMCS installation have the correct permissions. Directories should typically be set to 755 and files to 644.

6. Begin Installation:

   • In your web browser, go to the directory where you uploaded WHMCS (e.g., http://yourdomain.com/whmcs).
   • The WHMCS installer will begin. Follow the on-screen instructions.

7. Accept License Agreement:

   • Read and accept the WHMCS license agreement.

8. System Compatibility Check:

   • WHMCS will perform a system compatibility check to ensure your server meets the minimum requirements. Address any issues that arise.

9. Database Configuration:

   • Enter the MySQL database details you created earlier (database name, username, password). Add a table prefix if desired.

10. Administrator Details:

    • Provide the necessary information for the initial admin account, including username, password, and email address.

11. Installation Complete:

    • Once the installation is complete, WHMCS will provide a link to the admin area.

12. Secure the Installation:

    • Delete the install directory from your server. This is crucial for security.

13. Set Up Cron Jobs:

    • Set up cron jobs to automate certain tasks in WHMCS. You can do this within cPanel, usually under "Cron Jobs" or "Scheduled Tasks".

14. Configure Payment Gateways and Settings:

    • Log in to the WHMCS admin area and configure your payment gateways, tax settings, and other preferences.

15. Add Products and Services:

    • Set up your hosting plans, domains, and any other services you want to offer through WHMCS.

16. Integrate with Your Website:

    • Integrate WHMCS into your website by linking to it from your main site or embedding it in an iframe.

Remember to refer to the official WHMCS documentation for any specific details or troubleshooting tips related to your setup. Keep your WHMCS installation updated to benefit from the latest features and security patches.