I spent two hours trying to figure out why, whatever the configuration settings I threw at it, a laptop would not connect to a wireless connection.  Turns out the culprit was Norton Internet Security.  Only by running the Norton Removal Tool was I able to fix the computer.

Basically, ipconfig /all would give me the following message:

Connection-specific DNS Suffix . :
Link-local IPv6 Address . . . . . : fe80::ed42:547:5d1b:20ef%9
Autoconfiguration IPv4 Address. . : 169.254.32.239
Subnet Mask . . . . . . . . . . . : 255.255.0.0
Default Gateway . . . . . . . . . :

Ooooh, how fun, they say.  169.254.x.x is the IANA-defined black-hole.  Oops.  Of course, rebuilding the IP stack or turning off IPv6 didn’t help.  Sigh.  Probably recommending that everyone remove Norton now now that MS Security Essentials, AVG, Ad-aware, etc etc do a better job without destroying the computer while updating.