I have a home network with an ATT router and maybe 10 devices on it. One device, a dell latitude laptop running Windows XP is the issue here. This PC has always connected to the wireless network just fine, but today will not. I have worked with ATT, no help at all, but have gathered the following.
my laptop IP address is 169.254.xxx.xx. This IP address does not change when I reboot, and does not change when I do ipconfig/releanse, or renew, or when I do a dnsflush. (I dont know what these are, the ATT guys had me do them).
the router is not seeing this IP address. It assignes 192. ip addrsses to all other devices. I am almost sure that used to be the ip range for this laptop as well.
To a layperson, it seems that the router cannot assign an ip to this laptop, and does not recognize the one it has.
when I open network connections, it says signal strength excellent, but also "limited or no connectivity". The message also says "This problem occurred because the network did not assign a network address to the computer".
Yesterday, I did a ccleaner where I deleted a couple of programs (an ATT toolbar, a printer software thing, and I think that is it, but I must have done something to cause this laptop to suddenly not connect after 9 months of flawless performance.
I did a system restore to take me to a state before I did the ccleaner, but I dont think that helps with removed programs (if that is even the issue). I have also looked in my recycle hoping to find something there to reinstall, but nothing.
I am sorry if this is poorly worded. I am not a technical person, and am at a loss. Att said to take it to Office Depot. I am hoping someone here might have better advice, and can get me out of a mess I am sure I created.
You are on track with your analysis. The 169.254.x.x address is an APIPA address. Without getting into the technical details, a Windows system will self assign itself an ip in this range when it is unable to negotiate an address with your router.
You could try applying a static ip address to see if that works for the time being. Here is a video tutorial I have on YouTube regarding TCP/IP configuration on XP. The concept is the same for other Win versions.