You need to use following settings in your FTP:
Hostname: your-domain-name.com
Username: cPanel Username or the one you have created under cPanel > Files > FTP Accounts.
Password:  cPanel Password or the one you have created under cPanel > Files > FTP Accounts.

You can download an FTP client for Widnows at: https://filezilla-project.org 
Check screenshots at: https://filezilla-project.org/client_screenshots.php