How do you send free fax from my computer with out a fax machine or phone line?

Using internet faxing, you can receive and send faxes anywhere as long as there is a connection of internet. Try RingCentral services and get you online fax number.

Yes, you can send free fax from your computer if you have dsl or internet connection on your computer. there are few online services that provide the free fax service. one of the best is faxzero.com. its detailed functionality is elaborated on a blog that i have included in related links.