I have an iMac 21.5" mid 2010 and a 11" Macbook Air late 2011. I have been using the internal router in the iMac to provide internet access for the Macbook throughout most of the house with no problems. I recently relocated my Macbook  to a new extension to the house which is beyond the range of the iMac wifi signal.

 

 

 

I purchased a D-link DAP 1320 range extender which I located mid way and very quickly had both computers networked and sharing files. However, when I attempt to use the internet on the Macbook I can get no connection to the internet.

 

 

 

Unless I am very much mistaken when I set up the link initially I did not have to disconnect the ethernet cable from the iMac in order to have it talk to the D-link, but now I find this is essential! In fact when the iMac is connected to my modem via the ethernet cable the wifi icon on my screen top menu bar is replaced with an arrow in a triangle and the only options presented are: "Turn wifi off "AND "Sharing preferences" together with following greyed out : "Internet Sharing: On", "FrostiMac"(name of my wifi network)and "Channel: 11 (2.4MHz)". It will not seartch for networks.

 

 

 

I can find no references to anyone who has used a D-link in this way, and no suggestions for what to try. Can anyone help please? I am using Mavericks 10.9.2.