Wifi Problems

[BobinTexas]

From the sign-in name, you can see that I'm back to the iPad for posting. It's really just me, BobH.

Last night, while using my laptop web surfing, my connectivity dropped. The first thing I suspectect was the cable modem and router. After round-tripping them, I verified that the ISP could check my modem. All was well. To check the router I gt out the iPad and connected immediately. I then suspected my wifi adapter and changed it out with one working on the wife's laptop No joys.

When trying to resolve the problem, I tried a Windows software connection repair. It failed because it could not detect a wifi signal. This made me suspect the adaptor I tried three different 802.11n adapters - all working on other machines - and the built in 802.11.g adapter, which has been disengaged for months. Still no joys. I have made no settings changes and the problem occurred in the middle of a prolonged surfing session.

Having exonerated the ISP, the cable modem, the router, and the wifi receiver adapters, I can conclude only that something is wrong inside the PC, but I don't kow how to isolate the problem between hardware and software (XP SP3). So . . . . As a mere muggle, I'm turning to all you wizards and seeking your wisdom and wise counsel. Where do I go from here? Other than the attempted windows repair I've made no settings changes.

[viking33]

A/V and malware check?

[StuartR]

Can you do a system restore to a time when it was working?
If that doesn't fix it, do you have an image backup from when it was working?

[BobinTexas]

I can do a system restore but I'd like to exhaust all diagnostic avenues in order to find out (assuming one can) what caused the problem and fix it.

[BobinTexas]

Still working on AV and malware scans.

[akonobi2011]

This may sound elementary but is your wifi connection firewalled?

[Claude]

Even more elementary, you didn't hit the wifi button by accident? A few months ago, I traveled some 40 miles to a customer who did just that.

Failing that, try deleting the wifi network adapter in the device manager, reboot and see if Windows finds it again as a new device.

[jaystarter]

Similar experience to me last week, I'll just throw it in...my router is set to "auto select best wireless channel" which usually broadcast on channel 11. my laptop stopped connecting and completely by chance I found the router had switched broadcast channel to 1 and the laptop was still on 11. I set the router wireless channel to permanent 11 and the laptop connected straight away.

[Argus]

Difficult; as you have said there are several "suspects", and you've already ruled out some of them which is good. As some has mentioned it could be simple things, it happens. But I was also thinking if it could be a Winsock corruption; it will result in connectivity problems.

When one uses the button to do a "Windows software connection repair", as you said, I think it's the equivalent of release and renew and some more step(s). But if there's winsock corruption that’s not enough.

The solution then would be to run (at the command prompt, i.e. first run cmd.exe): netsh winsock reset

That is, type (all three words) and hit Enter, then exit, and restart the computer.

See, for example:
http://support.microsoft.com/kb/811259" onclick="window.open(this.href);return false;
Or:
http://windowsxp.mvps.org/winsock.htm" onclick="window.open(this.href);return false;

[Argus]

... and completely by chance I found the router had switched broadcast channel ...

That's a good one; never heard that. Wifi, eh.

[jaystarter]

... and completely by chance I found the router had switched broadcast channel ...

That's a good one; never heard that. Wifi, eh.

More to do with BT and Fibre (FTTC) lines and their "home hub" wireless router which comes with their non optional modem. There are various discussions among the BT user forums for using other replacement routers with the modem.
http://www.which.co.uk/news/2011/02/bt- ... 3--244076/

[Argus]

Mmm, yes, we sometimes hear complains about bundled equipment. What I meant with my comment was that with Wi-Fi we add several other layers of tech that can break, complicate troubleshooting etc.

I think we have similar things here from some ISPs. I'm a bit sceptic and old-fashioned, I want a simple line and my own router. But what do I know, I don't use such things as a home hub for everything and you name it; TV, telephone etc.

[StuartR]

I really like the BT home hub, because it provides a completely separate wifi channel for FON users, so that I can safely share my bandwidth with other people, and in return I get to use many hotspots around the world.

[BobH]

Thanks for all the good advice.

Since last posting, I've a) run complete malware scans with different software and found no problems; b) tried Win System Restore going back first 2 weeks then 4 weeks (long before the onset if issues) and the problem persists; c) tried the winsoc reset - twice - and the issue persists; d) discovered that iSSIDer sees no wifi, not even those other dignals from the neighborhood that have been around ( no new ones have popped up) BUT the Windows software shows my network and those in the neighborhood in the View Wireless Networks panel; e) changing firewall settings on the PC have no effect; f) wireless network status shows my connection with "limited or no connectivity" but shows speed s 144.5 Mbps and signal strength shows all 5 bars fully colored indicating a very strong signal. I also ran root kit revealer from a thumb drive. Although it showed several registry entries with null values, my googling turned up nothing to indicate any were problems.

I do have an Acronis image but I'm ashamed to admit that it is from months ago. (What can I say? I've got lazy since retiring not to mention having spent more than a month in hospital this summer. I used to have computer operators to do the grunt work.)

Ps: Can you tell me how to set the channel use option on the PC? I'll have to consult Cisco/Linksys to force a channel selection on the router.

[Argus]

I really like the BT home hub, because it provides a completely separate wifi channel for FON users, so that I can safely share my bandwidth with other people, and in return I get to use many hotspots around the world.

I'll have to repeat my reply from earlier today/yesterday:
That's a good one; never heard of that. (OT: If it's secure, and they say so, it seems to be good, and quite useful.)

[StuartR]

...Ps: Can you tell me how to set the channel use option on the PC? I'll have to consult Cisco/Linksys to force a channel selection on the router.

It will be in the properties of the Wireless Adapter device.

[BobH]

Thanks, Stuart.

Since posting last, I purchased and installed a new Cisco E2500 router. The problem remains with this one device of the 9 that we use from time to time. The router is set to allow many more simultaneous sessions, jsyk.

The thing that most puzzles me is that Windows can 'see' the networks represented by routers in the neighborhood - including mine - as evidenced by the View Networks CP code; yet the apps (inSSIDer, Firefox, et al) running below the OS do not. From this I deduce that the receiver adapters are working properly. I have disabled the on board adapters on swapped several USB wifi adapters around several machines. Every machine except this HP laptop works with any adaptor. The HP will not work with either the onboard 802.11.g or the various 802.11.n ones I tried. Prior to the onset of this problem, the HP worked with either a USB n or he built in g.

I can only imagine that the problem exists physically on a board or chip hardware component that no diagnostic has yet revealed, or Windows has lost a connection - probably in the Registry or in an API. Again no dags point to a problem. I've tried reinstalling drivers for the USB adapters to no avail. Without being to get online, I can't download directly to this machine. I haven't tried using a different one to get driver updates on a thumb drive. Perhaps it's time for me to crank up sneaker-TAM.