Before you go out and buy a cable the length of your house, why don't you move closer to the modem and plug it in with a shorter cable you might already own. Also, there is no guarantee this will work as your modem is also a router, even if it does not have wifi capabilities as you are suggesting. So it is possible it is the modem's firewall blocking your connection and not the separate wifi only router most likely setup in a bridge mode to just distribute the connection.
If you find that it is the modem firewall blocking the connection you should be able to call your ISP to get help on where to open up the router to allow additional activities.
Hello Ben and Nancy.
My iMac is too clumersum to move it around. So I bought the cable and did the connection thing and what do you know?! . . . it still didn't work.
At this point of my desperation I was looking for someone to blame and I choose Dreamweaver itself. So I downloaded Filezilla and tried that app. Turns out the fault was mine. (remember I'm new to this). I was imbedding the index file into a folder called images and then uploading that into the public_html folder. I don't know where I got that idea.
So the mystery is solved and I'm the culpret. Thanks to the both of you for your help.