Lost setting for external fax

Hi, I'm not too sure if this is your field but I cannot find anyone to assist me with a problem I have, and being a senior citizen I have had no formal IT training . So, if this is not something you handle I apologize in advance for bothering you. Background: My OS is Windows XP. I use ADSL for Internet access. The DSL router I have does not have faxing facilities. I fairly often need to send faxes so I downloaded and registered Snappy Fax V4.When I discovered from my service provider, Telkomsa.net, that my router does not support faxing, I coupled an external fax, US Robotics Sportster Flash 56 K , to my PC. This fax modem works well with Snappy Fax and I am able to send faxes. However, and this is my problem: each time I shut down my PC I loose the setting for the fax. To overcome this problem I have to disconnect the fax modem, shutdown the PC, reboot, reconnect the fax, go to the control panel and select "Phone & Modem", this then searches for the fax and once it finds the US Robotics fax modem I can go to Snappy Fax this then identifies that my fax modem is the US Robotics and I can then proceed to send a fax. As you can imagine, from the above, it is most frustrating to send a fax. I have written to Microsoft and Snappy Fax about my problem but have had no reply from either of them, hence me contacting you. What I want to know is why the setting is not retained when I shut down my PC and is there a means of overcoming this and how to go about it?. If you can possibly help me I would be most grateful. Kind regards Hilton Ward