iMac Won't Connect to Airport

Hello, I have a MacBook since June, and it's worked fine, no problems. My dad doesn't have wireless internet, so everyday I have to bring my wireless router to his house, and hook it up, blah blah blah. So, to save me the hassle, he bought AirPort express (I have AirPort extreme).

Anyways I've hooked up the Airport Express properly, and double checked the manuals just to make sure. All is good. However, the light never goes green like it's supposed to. It either flashes orange, or stays orange. My dad's iMac, and my MacBook can both detect it, and they can connect to the network with it (sometimes), but they can never use it to connect to the internet. I've checked the manual and according to it I've done everything correctly.

I need some help on this one because it's a pain to drag my router everywhere I go with me and hook it up everyday.

Any insights?

Reset the APX and start again. Another thought I had is that you can share the Internet connection if it is connected directly to the iMac and not use the APX at all. Check out "Share your Internet connection" for instructions.

OK thanks, I actually managed to get AirPort working, and I took it to my friends house today and it worked there.

However I will definitely check out the share your connection thing. Seems cool.