Limited or No Connectivity WinXP SP2 Bug
I'm sure some of you have heard of this problem. There is a NAT bug in the SP2 for WinXP which Microsoft has addressed but not fixed yet. It causes a wireless (and sometimes wired!) connection to not be able to acquire an IP address, claiming the "Limited or No Connectivity" error message. MS deployed a hotfix which doesn't work. Many people have tried fixing it different ways but I have tried them all, and I have resorted to the last step: downgrading to WinXP SP1. I have just nlite'd an ISO and I'm going to install it in a minute.
I have wasted an entire day trying to fix it. Things I have tried to fix it:
Some .reg file I found
Setting LAN IP manually
Setting nic speed manually
Shutting down all devices for several minutes, restarting router, ap, computers (in that order)
Last step - Uninstalling SP2