We have an iMac 2011, running Mavericks. Recently, we have been having trouble using the internet via wifi, after my brother (who was using the computer) got blocked from the router. After doing so, he changed the mac addresses to circumvent the block. Fast forward, after it gets unblocked and everything... It still doesn't connect to wifi networks. Even in "Install OSX Mavericks" from an external USB, it does the same thing.. - Choose network - Type Password - Does that stupid connecting animation - Ends up with a ! through wifi saying no internet connection - Either says "Self assigned IP 169.bu.ll.sht" or "No IP address" - Nothing works, tried new location, DHCP, new mac address, new computer name, net netbios name, all of that ****. - I even tried using MY computer (connected to internet) to share the connection to the iMac, and that doesn't work. Ethernet does however work on the iMac. I really don't know how to fix this.. I've done everything I know and it doesn't work. I've resorted to just using it via ethernet because it is too much of a hassle to keep trying the same processesses (recommended by the internet) that don't work. What should I do?