I use to use WS_FTP back when my employer was paying for it (they had a company wide license) so I never had to deal with an annual renewal process. However, now I use and highly recommend one of two free (GNU GPL license) FTP solutions. First is
Filezilla which I usually recommend to anyone looking for an quick and easy to use FTP solution. And second is
WinSCP which is a much more secure FTP software since it can do FTP over an SSH connection.
Also, since I never like to miss a chance to remind people that Windows Explorer has a built in FTP client. I don't use it much since I'm not too sure how secure it is, but it's is nice to use once in a while when you're using someone else's computer that doesn't have an FTP program installed. To use just open Windows explorer and enter
ftp://username@example.com where username=login name and example.com=domain name. Windows will then prompt you for a password. Enter one and now use this connection just like you would any other drive in Windows Explorer. You can click and drag files back and forth between drives and even edit file while still on the server.