FileZilla Client is a free, open source FTP client for Windows.
It supports FTP, SFTP, and FTPS (FTP over SSL/TLS).
The client is available under many platforms, binaries for Windows, Linux and Mac OS X are provided.
Links:
Filezilla Client for Windows (32 Bit): https://filezilla-project.org/download.php?platform=win32
Filezilla Client for Windows (64 Bit): https://filezilla-project.org/download.php