Samba is a bad idea on a public Unix box, although you could make a VPN to secure it. FTP, STFP, or SCP would all work fine if all you really want is file copy. FTP is the easiest but least secure. Another option that is trivial to set up and may suit you would be to use Apache and .htaccess to password protect a browsable location on your unix file system, with acess via IE on the Win32 box. This is not secure (plaintext authentication) but you could use HTTPS/SSL to fix that.