My iMac can't connect to internet wirelessly
I purchased a 27" iMac in 2013 version 10.8.5. For no apparent reason, my iMac won't connect to the wireless. According to my iMac I have full bars but when i open my browser and try to connect to any website, the page won't open. The browser continues to try to load page for some time and eventually displays "Safari can't open the page "http://<website address>/" because the server where this page is located isn't responding." I had, prior to this problem, and still have, after this problem, other devices connected to the same wireless router without problems. My current wireless router doesn't have a password, however, there are no neighbors close enough to connect to my wireless router. I've restarted my computer, shutdown my computer, restarted my wireless router, turned on/off Wifi to no avail.
Per System Preferences>Network>Wifi, i have a green light with status: Connected. My Airport Utility however switches back and forth between connected and not connected. But regardless of what my Airport Utility says, I can't access wireless. I'm looking at the IP address and my macbook pro is connected to the same IP address without any problems. Does someone know what's going on?
Please help!
iMac, OS X Mountain Lion (10.8.5)