Mac Forum / Applications / Mac Applications / July 2008

I sold my old 1Ghz PowerBook G4 to a friend who lives several hundred
miles away from me. Another friend had borrowed the PowerBook before I
sold it.

I deleted everything off it before I mailed it to my friend and I set up
a brand new account for her and I wiped out my old account. I also set
it up for an old AirPort base station which I also sent to her and this
was all working fine before I sent it on my cable modem.

Now, she can't get the PowerBook online via her cable modem using wi-fi
or ethernet cable. We've spent several hours troubleshooting this. The
AirPort card in the PowerBook works fine because she can share files
with it between it and her Mac mini, but it just won't go online.

Finally, tonight, my friend called her ISP and she was told that the
PowerBook has an incorrect IP address even though its set up for DHCP. I
had her go into network preferences and switch to manual mode on both
the ethernet port and the AirPort port, but all the fields were empty.
So I had her try to put in a new IP address that was 2 more than the one
her Mac mini has (which works fine via wi-fi on this AirPort base
station) and I had her put in the same subnet mask and router addresses,
but still, it reports an incorrect IP address.

So, in a fit of frustration, I had her move all the system preferences
to the desktop and reboot. After she logged into the PowerBook, it
started up the Internet setup wizzard. She told it she wants wi-fi and
it let her access her AirPort base station again, but still, it reports
that same invalid IP address.

So how in the world can she get rid of that bad IP address without
reformatting the hard drive and reinstalling the OS? I am very Mac
savvy, but this has me stumped.