Hey, I just clean installed ML on my 2010 Macbook Air 13", it was having some slowing problems and it fixed it pretty well. But now my wi-fi is not working. I couldn't connect to any wi-fi networks, it keeps showing the exclamation mark on top of the wi-fi icon. I use it to study and work, my other computer is an iPad, so I really need this computer. I have everything backed up, but my network configurations didn't restore with time machine. Help.