Please do a search in the Web Hosts & ISP forum for web hosts that will fit your needs. Be aware that most free hosts will shut down a site using a fairly popular BBS due to CPU usage. Their servers are so loaded with accounts they can't afford the cpu cycles to go to one cgi process. The only host I haven't heard of killing people's accounts is http://www.f2s.com

The OS you're using to upload the files is irrelevant, only the OS of the host is relevant.

Review your CuteFTP user's guide or help files for instruction on how to use it. Then just follow the installation instructions provided in the help directory of the UBB zip file.