all FTP programs not working on my Windows xp

None of my ftp programs are able to find their host.

Here's the rundown:
*I've tried cuteftp, wsfts_le and wsftpPro
*I've been FTPing since 1995 so I'm not a novice.
*All of these programs DID work several months ago.
*I have not changed any of the settings.
*I have tried to connect with and without xp's firewall
in place.
*I am able to connect to the desired servers on my xp pc
at work.
*I've installed new versions of WSftp and CuteFTP
*I've even tried ftping into my ISP's server so as to
eliminate the possiblity of DNS not resolving IPs

Nothing works even though it did a few months ago.

What could be corrupted? what should I re-install? and
how?