Fax answering phone

>I am getting so tired of this problem. I am running home basic and the
> computer keeps thinking it is a fax machine and answers my phone. If I
> don't
> pick it up on the first ring, the caller and I hear the sound of a fax
> machine. Very hard on the ears and also makes us miss alot of calls and
> has
> alot of people angry because they can't get through. We don't seem to
> have
> this problem when we are online. Our voice mail picks up. I spent the
> afternoon on the phone with the phone company thinking it may be something
> in
> the line, but all is good there. I sure hope someone can help.