iMac cannot connect to internet, but all other devices can?
Ok So I have an iMac, two iphones, and a mac book air in the house. The mac book and iphones can connect to my chinese tp-link router, and connect to the internet wirelessly just fine. The iMac however, everytime I tried to connect to the internet via the Wi-Fi signal through the tp-link router, the wifi signal on the very top right hand corner of the screen has an exclamation mark ⚠ on the wifi bar, and it says Alert: No Internet Connection. The ethernet works fine connected directly to the iMac, and I can access internet via ethernet wire setting, but not wifi-setting from my tp-link router.
What I've narrowed it down to:
It is not the problem with the router, because it is configured so that every device I've tried, except for the iMac works with the router.
It is not the problem with my internet connect, because all other devices works, except for iMac.
It is not the problem with my internet card on the iMac, because I was able to connect with an airport extreme about two weeks ago via wirelessly.
It is not the hardware problem, like I said, ethernet socket, internet card, they all work.
It has nothing to do with the software update, the software is up to date, running on Mac OS X, Version 10.7.2 lion.
It has to be a software issue, something to do with the configuration of the network.
I've already looked everywhere on the apple discussions, I found similar problems, but they were either unresolved, or unrelated to my problem. So what did I mess up on?
Best
Brian
iMac, Mac OS X (10.7.2)