XP has it's own Fax facility. This is found in All programs>Accessories>Communications.
From memory this is not installed in a typical XP set up, but can be accessed from Control Panel>Add/remove programs>add windows components.
I am doing this from memory, I will check later when I am home, but in the meantime, this will bump you up the postings, in case somebody more knwledgeable comes along!!