Thanks for the feedback and that you got your fax sent. HERE is an example of a "data/fax modem" that could be installed in your PC.  And, as noted it would connect to a standard analog voice telephone connection. Actually, unless you regularly send or receive faxes, services like you used is the best option.   If you regularly send or receive faxes a better option is to buy an All in One printer/scanner that also has built in fax capabilities.  THIS is an example.  
Hello, My computer on Win 7 x64 Ultimate. I scan a handwritten letter in document pdf format and save it under my scan documents in my computer HD. How could I send this scan-document [pdf]  from my computer to a distant  fax in a home that has only fax facilities?   Thank you for your help. Snow  
How could I do Faxing from computer?