I have a Macbook Pro from 2011 currently running OS X Yosemite 10.10. Before i upgraded to Yosemite, i was experiencing a common wifi issue that was that the wifi disconnected from the internet and it couldn't be turn on or off; sometimes, when i turned on the mac, a "No hardware installed" message showed.
I replaced the wifi card but the problem persisted and now that i upgraded the OS, the configuration didn't recognise any hardware and no Wi-Fi interface is shown on Network Preferences.
I know there is a file
Library/Preferences/SystemConfiguration/NetworkInteraces.plist that contains these interfaces information.
Is there anyway that i can configure this file to add the wifi card? or is there something else that i can do? knowing that replacing the wifi card didn't solve the problem and that it may be a software issue?