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Help - Windows 11 lost internet connectivity

TimCurtis — Fri, 04 Aug 2023 10:39:20 GMT

On my PC in Windows 10 I had to run a command to get IPv6 working.

The command was "sc config Tcpip6 start= demand".

I upgraded it to Windows 11 and no IPv6 connection so I ran the same command 😭

I've now no connectivity at all and the Windows trouble shooter hasn't been able to fix it and at the moment I've no idea what to do.

Any suggestions - only helpful ones please - would be most appreciated.

Re: Help - Windows 11 lost internet connectivity

gg30340 — Fri, 04 Aug 2023 12:19:48 GMT

Have you tried resetting your network/Internet connection?

To reset network settings: Start menu > Settings > Network and Internet > Advanced network settings > Network reset.

Re: Help - Windows 11 lost internet connectivity

TimCurtis — Fri, 04 Aug 2023 13:29:45 GMT

@gg30340

Yes I did as it's part of the Windows troubleshooting process.

I've also tried a USB wifi dongle and an ethernet card I had spare and nothing changes.

That command I used must have corrupted something but unfortunately my last back was just before I updated to Windows 11 so rather loathe to go back to that.

Re: Help - Windows 11 lost internet connectivity

gg30340 — Fri, 04 Aug 2023 13:53:02 GMT

By posting here I am assuming you do have Internet access on other devices and that its not a problem with your broadband connection.

Have you checked in the Device Manager to see if it is showing any errors.

Have you gone into the "Services" to ensure that all the relevant services for Network are running and not set to "disable"?

Re: Help - Windows 11 lost internet connectivity

TimCurtis — Fri, 04 Aug 2023 14:16:45 GMT

@gg30340

Yes I've a spare Windows 10 PC and full connectivity with that.

All the Network services are running normally and of the disabled services nothing seems to relate to this networking problem.

In Device Manager there are no errors.

Re: Help - Windows 11 lost internet connectivity

TimCurtis — Fri, 04 Aug 2023 14:25:24 GMT

I've uninstalled the adapter re-installed the drivers but no change.

The adapter is connected to a switch & that is showing a gigabit connection so physically all is well.

Re: Help - Windows 11 lost internet connectivity

gg30340 — Fri, 04 Aug 2023 15:14:20 GMT

Check that the services TC/IP NetBios Helper is set to manual, trigger start.

Re: Help - Windows 11 lost internet connectivity

gg30340 — Fri, 04 Aug 2023 15:24:08 GMT

The last thing I can think of would be to run check disc in a command prompt chkdsk C: /r which should find any damaged or corrupted Windows files and replace them.

Re: Help - Windows 11 lost internet connectivity

TimCurtis — Fri, 04 Aug 2023 16:50:41 GMT

@gg30340

Been on with MS support & restoring back to my Win10 version & then upto Win11 again

Re: Help - Windows 11 lost internet connectivity

TimCurtis — Fri, 04 Aug 2023 17:06:39 GMT

@gg30340

Well recovery from Win11 to Win10 was pretty quick and seemly painless.

I'll leave it a few days before I go again to Win11.

Thanks for trying to help but it looks like I'd really corrupted something that wasn't fixable.

Re: Help - Windows 11 lost internet connectivity

Carlusha — Fri, 04 Aug 2023 17:12:29 GMT

@TimCurtiswrote:

Well recovery from Win11 to Win10 was pretty quick and seemly painless.
I'll leave it a few days before I go again to Win11.
Thanks for trying to help but it looks like I'd really corrupted something that wasn't fixable.

OK, great but even at that point, you have nothing to lose by running @gg30340 's suggestion of :

The last thing I can think of would be to run check disc in a command prompt chkdsk C: /r which should find any damaged or corrupted Windows files and replace them.

This will ensure you are "uncorrupted" prior to your second attempt.

Re: Help - Windows 11 lost internet connectivity

licquorice — Fri, 04 Aug 2023 20:45:28 GMT

Hmm, you shouldn't have to run any commands on either W10 or W11 for IPv6 to work.

Re: Help - Windows 11 lost internet connectivity

WSH — Fri, 04 Aug 2023 22:31:25 GMT

The Sc command is a way to update the registry. That will be where the corruption is. I’m not sure Sc was updated beyond Windows 8. Personally, I think using regedit is a safer bet.

As Liquorice says, Windows has been dual stack since Windows 7 and you should not need to run anything to get IPv6 to work. In my experience any problems with IPv6 are usually the router or Windows temporary addressing, where Windows refuses to give up an IPv6 address even though it has deprecated it. If you had IPv6 working and it suddenly stopped that will probably be the reason. Windows 11 is a lot better behaved than Windows 10 in this respect.

Re: Help - Windows 11 lost internet connectivity

TimCurtis — Sat, 05 Aug 2023 16:16:46 GMT

Looks like one of my VPNs (FastestVPN) prevents the IPv6 connection being established.

Had this installed on my PC and a laptop both of which couldn't get an IPv6 address but as soon as I uninstalled it IPv6 was back.