I have an old macbook, early 2008 running Mountain Lion. The wifi stopped working suddenly a few days ago. It was working then stopped. I had not updated or installed anything. I have been trying everything I could find online to fix it but nothing helped. So I decided to erase the hard drive and reinstall the os thinking it might fix things and I've nothing to lose at this point. I held down command r as I restarted. I chose disk utility, then the disk to erase, the format style, and name, then clicked erase. A confirm box came up and again clicked erase. Then nothing happens. I did this several times with same results. Now when I quit disk utility and shut down when I turn the computer back on all thats there is the same window that you start up holding down command-r. I don't know what I've done ore what to do.