No airport base station have been found!!!!

Okay I give up! I first started off with my bf's older (4yrs?) MacBook labtop and an airport express. I tried to get it to work and struggled with it

for about a yr and a half. It would always flash amber. When the light did turn solid green it would say I cannot connect. I have airport on my cell phone

And you could watch it change back and forth from yellow to green! Finally frustrated enough, ( since me and my boyfriend couldn't use the wifi for our iPads

and iPhones, I ended up getting a brand new MacBook air and a airport extreme. I followed the instructions perfectly ( hooked up my Ethernet cable from

my shaw box, hooked up my USB for my printer and plugged it in. The light went from the green to solid amber to flashing amber, I then went in to utilities

and opened airport utilities only to find the same message I got with the old Mac and express! It said " No airport base station have been found!!!! I tried everything too! The ironic thing is it comes up on the old Mac but on nothing else! However I need to run my new MacBook air wirelessly!

I have tried:

- clicking on other airports- nothing

- unplug, wait, plug back in

- phoned Shaw he told me to unplug the shaw box and the airport, plug the shaw box back in wait for it to go online and then plug airport back in. He confirmed it was reading an address so the box was working fine and hat it is up too date.

- pressing the restart button while plugging it back in

- moving the airport, however it never been further than .5' away! There's no metal or any other interferences

- restarting the computer

No matter what my air just keeps searching for the airport but nothing is ever found! How does this happen!? I was always a huge apple fan but I'm having regrets!!

Can anyone out there please solve this nightmare for me?

Thanks