Vista laptop, can't connect to wireless router

[Jax_Minnesota]

Hello, and thanks for reading this post. 

I've got three laptops all sharing a wireless home network.  My two XP machines work fine, but the Vista machine won't connect wirelessly.  I can, however, connect to that same router using an ethernet cable on that machine, and to other wireless networks.  The laptop had connected wirelessly fine to my home network up until two weeks ago, but stopped at some point while our little kids were playing net games on it.  --One of them may have hit a security setting or wireless setting.  For some reason they'd accessed my wife's profile (admin), not their own (kids zone).

Any suggestions? 

Hardware --
The laptop is a Compaq Presario CQ50, with 2GB of RAM and a Pentium T3200 CPU.  The modem is a HDAUDIO Soft Data Fax Modem with SmartCP.  My router is a D-Link DIR-655, which of course is 802.11 N protocol.  Both laptop and router were bought at Microcenter about six months ago. 

Software --
My Vista build is Home Premium, with SP1 installed.  I'd rolled back from SP2 a few days ago while trying to fix this error. I run ESET as my AV and firewall.  The modem driver is up to date, latest driver edition from 2007.  The wireless connection is enabled, and can see five or six live routers in my neighborhood.  When I try to connect to my home router I get a diagnostic screen back that says either cannot connect or have a limited connection.  --The laptop sits right next to the router, so there is nothing physically blocking it, and the other PCs around the house have an excellent signal.  I am using an open authentication, with WEP security. 

Now, the router itself connects to my ISP via a city-wide wireless system, but that connection seems to be working fine with the other two computers.  As I mentioned earlier, if I connect as if I am roaming, I can connect to the city-wide network fine. 

Calling the city-wide ISP, I was told that "Vista sometimes does this.  You may have to unplug the modem, let it rest for 20 minutes, and start it up again." I did this, taking it out from the back panel.  However, I did not start up that laptop while the modem was out.  I put it back together, and have the same symptoms. 

Thanks for any support or advice y'all might provide.  -Jax

[Quantos]

Will the Vista machine connect if one of the other computers are turned off?

[techblue]

Are your wireless drivers still there or up to date? That could be a possible fix. Vista on some installs tends to do such strange things.

[Jax_Minnesota]

Replying to two responses. 

First, to Quantos:  No, the Vista machine won't connect to my home wi-fi router regardless of the status of the other two working machines. 

Second, to Techblue: Windows reports that the drivers are up to date.  The publisher is CXT, the driver date is 11/15/07, and the driver version is 7.70.0.0. 

We've been using this laptop via our ISP's roaming option connecting directly to the neighborhood wi-fi port for about 24 hours now.  No problems with it with this workaround.  Therefore I'm wondering if this kind of modem have a ROM that needs to be refreshed.  I keep thinking about what the ISP's support guy said.  It's common for the software guy to blame the hardware guy, but in this case I am not dismissing what he advised.  Should I have uninstalled the driver prior to removing the wireless chip, then re-booted to cycle it as having been physically removed?  Also, I've not yet called the D-Link folks.  I believe the router has an option to upgrade to another security protocol, and I wonder if that would force a refresh of any bad settings.  Thanks to all who've read this post. 

[Quantos]

Will the Vista machine connect if one of the other computers are turned off?

[Jax_Minnesota]

No, the Vista machine still won't connect if I turn off one or both of the other computers.  It sees the home wi-fi network, even says it is connected if I try, (with a limited or no signal), and I can't get to the internet with it. 

[Quantos]

Okay, we have a starting point now.

I want you to try this on the Vista machine.

Start Button>Run
Type in cmd and hit enter.
At the prompt type in "ipconfig /release /all", just don't include the quotation marks.
Then reboot the computer.

[Jax_Minnesota]

OK - trying Quantos' suggestion, I ran ipconfig /release /all at the CMD prompt.  Note for readers, the SEARCH field at the start menu can be used as a RUN dialog box.  Alternatively, you can get to CMD (~a DOS prompt) via the All Programs menu, under Accessories, spelled out as Command Prompt.

The ipconfig command came back with an error which said "The requested operation requires elevation."  --meaning the operating system needs to confirm that the user is an administrator, even though I was logged in as such.  I fixed this by going to the All Programs menu, finding Command Prompt under Accessories, right clicking on it and clicking on "Run as Administrator."

Now, the ipconfig command reported back that "The operation failed as no adapter is in the state permissible for this operation." 

[Quantos]

That's a syntax error.  Let me find the correct syntax for you.

[Quantos]

I'm really sorry about that. 

Try this instead.
ipconfig /release

I don't know what I was thinking with the /all.  My story is that I was tired, yeah, that's it, I was tired.