It can be a little work to install and configure the fax features in Windows, but once installed, they can be used just like a printer by all Windows applications. Installing the fax feature makes the Fax Console available. From the Fax Console you can send, receive, and manage all your faxes just like an e-mail client.
The Fax Console includes the Send Fax Wizard, which walks you through defining the fax recipient and cover page. Scanned documents and word processor documents can also be sent via the fax capabilities.
The Fax Cover Page Editor is an application where you can create your own custom cover pages to include with faxed documents.
Finally, if you don't have a modem installed, you can sign up for a service that allows faxing through the Internet.