While on linux you can use rsync which is very powerful it sometimes need quite some technical knowledge to install rsync properly on a windows machine you could use i.e. bonkey a free tool which can make (automated) backups at your windows platform over i.e. sftp. Our rsyncvault service provides this as an option and works perfectly with bonkey. In the below video you can see how to setup bonkey for the first time.
Show video on how to install bonkey for your needs.
Download bonkey: http://sites.google.com/site/thebackupmonkey/home/bonkey-for-windows
Bonkey is also available for Mac OS X, download this version here: http://sites.google.com/site/thebackupmonkey/home/bonkey-for-mac-os-x
