I had a disk error that rendered my Mac unbootable. I repaired it with Tech Tool 4, but now networking does not work.

Network Preferences reports that my Ethernet cable is unplugged. I know this is bogus because when I boot from an emergency partition, networking works correctly.

Furthermore, wireless networking is also broken, which I tested with a known-good Wi-Fi dongle.

Whenever I try to change Network Port Configurations by creating a New or Renaming an existing one,

example:

I get this message in the console:

Error - PortScanner - setDevice, device == nil!

Error - PortScanner - setDevice, device == nil!

In sets of two as shown.

When I try to invoke the Network Diagnostics app, it immediately crashes.

My first thought is to reinstall Tiger with the Archive and Install method so I don't have to reinstall all my applications but I have lost my Tiger installer disk.

My next thought is to buy Leopard for $107 on Amazon.

If there is any way I can just repair my Tiger install I would be happy to save that money, though. This is not my main machine and I am loathe to put more money into it.

How can I recover my network functionality?

UPDATE: I found my Tiger install disk and tried an Archive and Install. It failed with an unhelpful error message along the lines of "Can't install, try again". I tried again but had the same error. My guess is, some corrupt or missing file in my User folder is preventing migration.

I have a backup created with Super Duper that is a bit out of date but will startup the machine (with functional networking). I would love to just copy over the file(s) that got messed up but I don't even know where to look.

What is the likely location of the System files that would cause the aforementioned symptoms?