Can't see my computer...help!

OK please no bashing.  I had my ATV setup in my old house with the ATV upstairs and my main computer in the basement with a d link.  I was able to see my network and all hardrives attached to the home computer once I shared.  I have moved and my ATv was not used in 3 months. Also the home computer died.  My setup is a Sony laptop with a 1.5 exteranl attached.  I use the laptop wirelessly via an Airport Extreme.  Boxee still shows the old computer and even with theings shared I see nothing with the new laptop and externals....help!

 

OK please help.  I understand to those who know this stuff its easy but I am 44 and am lost.  I was able to go on my laptop and share folders.  I am in Boxee now and I see the external drive.  So I see my "H" drive....click on it and see all the sub folders.  I click on my ITunes Music subfolder and I get a "user name" Password.....I have tryed everything.  I put in the Airport Extreme password, my computers password...it just bounces back to enter that info again.....where am I going wrong?