Once the Microsoft Service is installed, it will run automatically when your computer is turned on, listening for the phone to ring. When it does, you will see a message in the notification area (bottom right of your screen). Simply click this message to start receiving the fax. Once the fax is received, it will be available for you in the Fax Console.
As with other fax software for Windows XP, you can configure the Fax service to automatically start receiving faxes, for instance when you are away from your computer. You need to open the "Printers and Faxes" folder from the Control Panel to do this.
In the "Printers and Faxes" folder, right-click the Fax icon and select "Properties"
Click the "Devices" tab and click "Properties"
Click the "Receive" tab and under "Answer Mode", choose "Automatic" and set the number of rings
You can also choose to print it on your printer when a new fax is received and you can tell Windows to save a copy of the fax in a specific folder
The Microsoft Fax service offers enough functionality to serve as a simple fax utility, but if you need something more powerful, you may want to take a look at some more sophisticated fax software for Windows XP, like WinFax Pro.