OK, this is an odd one. I have Comcast cable internet; recently added a Trendnet router. We have a Compaq desktop hardwired to the modem/router, and two HP laptops (both running Vista) connected via wireless.

Both laptops are the same model (dv2310us).

One of the laptops (laptop A) was purchased in February, and has been on the network ever since. A few days ago it was bluescreening with tcpip.sys errors, but that seemed to clear up on its own and has not happened for a few days. I never thought it would be related to the below, but now I'm not sure...

The second (Laptop B) was acquired about a week ago, and I've had nothing but trouble getting it to see our network. I was able to get online fine the other day to download FF, OpenOffice, and Pidgin, but then it died. And I haven't been able to get any sort of connection since.

ipconfig on Laptop B gives me "media disconnected". A TCP/IP reset worked for a few seconds, but no sooner did my homepages load and I try to navigate to another page and get disconnected.

The desktop runs XP; whenever I try to get Laptop B on the network now, the desktop pops up "IP conflict detected" (but the desktop connection is never interrupted).

Now the desktop won't even see Laptop B (I'm running Network Magic software that came with the router; desktop and Laptop A have it; Laptop B doesn't yet).

Any ideas?

can you post an ipconfig /all for all three machines - make it clear which is which

ipconfig /all

TWO Methods to do that - some people have problems with ONE----

ONE ---------------------------------
start
run
cmd
ipconfig /all

rightclick in the box
select all
enter
control key + C key - to copy
then reply here and
control key + V to paste

TWO -----------------------------------------------

Start, Run, CMD to open a DOS window and type:

IPCONFIG /ALL >C:\RESULT.TXT

Open C:\RESULT.TXT with Notepad and copy/paste the entire results here.

OK, I'm not quite sure what happened here...

Rebooted modem/router, put everything back one by one (basically rebuilt the network from scratch): desktop and laptop A OK, laptop B no-go (I got local access only on the public wifi, but no internet). My network has MAC filtering enabled; usual procedure to add a device is unlock the network, connect the new computer, make sure the router sees it and relock. Laptop didn't see anything (save for the public wifi and a few secured networks in the building), and the router didn't see the laptop.

Booted Laptop B into Knoppix to see if it could see the network, Knoppix couldn't find any supported network adapters.

Shut down Knoppix, rebooted back into Windows, tried again.

It worked. Laptop B could see our network and vice versa. I was able to add it on no problem, and I'm no longer getting any IP conflicts from the desktop (I still don't know what IP address Laptop B was trying to assign to itself previously).

The only thing I can think of is Laptop B's network adapter somehow got pooched by an update/other Vista download, and Knoppix reset it somehow?

So for now, it's inexplicably solved...of course I'm going to keep a close eye on it for the next couple days.

ok the IP on the 3rd machine is one that windows assigns when it cant find the dhcp server

so one thing to do would be to
turn off modem / router PCs
then turn the modem on - allow a few mins
router on all a few mins
one PC at a time

if still the same
next would be to go into device manager under the wireless adapter and disable and then re- enable
see if that helps

if not - then recheck the firewall