One device can't connect to 2.4GHz Wi-FI

AcerA515-45
Windows 10 Pro 22H2
Qualcomm Atheros QCA61x4A Wireless Network Adapter

I have no idea when this issue started but my laptop no longer connects to 2.4GHZ Wi-Fi - "unable to connect to this network". I can connect to 5GHz Wi-Fi and to 2.4GHz using an ethernet cable but not 2.4GHz Wi-Fi. I have two separate networks: one is my regular ISP and the other is Starlink. I can't connect to 2.4GHz Wi-Fi on either of them so it doesn't appear to have anything to do with the ISPs or the routers. All other devices (laptop, phone, tablet, TV, PlayStation, Android TV dongle) can connect to 2.4GHz Wi-Fi, it's only my laptop that can't.

Things I've tried so far. Some I know to do, others are online suggestions:
1) Power off the router. Wait 30 seconds then restart.

2) Remove the 2.4GHZ networks from Manage Known Networks.

3) Uninstall the Adapter Driver. Reboot PC for it to reinstall.

4) Disconnect from all Wi-Fi access points, set PC to Flight Mode. Open Command Prompt as administrator and enter ipconfig /flushdns, then enter sfc.exe /scannow. When the scan completes shut down PC, wait about 30 seconds, then restart PC.

5) Update the drivers via Device Manager - Automatic (no updates available) and Browse > Let me pick from a list of available drivers on my computer. Tried the two that were in the list: Microsoft and Qualcomm.

6) Turn off "Allow the computer to turn off the device to save energy" in adapter Properties under Power Management.

7) Made sure the Preferred Band in the Advanced adapter Properties isn't set to Prefer 5GHZ Band. I even tried setting it to Prefer 2.4GHz Band but no luck. I put it back to the original setting of No Preference.

8) Uninstall VPN.

kiwichick said:

Qualcomm Atheros QCA61x4A Wireless Network Adapter

I have no idea when this issue started but my laptop no longer connects to 2.4GHZ Wi-Fi - "unable to connect to this network". I can connect to 5GHz Wi-Fi and to 2.4GHz using an ethernet cable but not 2.4GHz Wi-Fi. I have two separate networks: one is my regular ISP and the other is Starlink. I can't connect to 2.4GHz Wi-Fi on either of them so it doesn't appear to have anything to do with the ISPs or the routers. All other devices (laptop, phone, tablet, TV, PlayStation, Android TV dongle) can connect to 2.4GHz Wi-Fi, it's only my laptop that can't.

Your laptop has multiple network adapters (all with different MAC addresses) - ethernet, wifi, Bluetooth, NFC and virtual adapters, e.g. for loopbacks. Your Qualcomm Atheros QCA61x4A Wireless Network Adapter is a SoC offering 3 different radios (dual-band wifi and Bluetooth) all on one chip.

From the symptoms you describe and the troubleshooting measures you have tried, it suggests possible registry corruption of the network adapter information recorded for just the 2.4GHz radio. My reasoning is that you have already tried connecting unsuccessfully to two different 2.4GHz access points.

For a wifi connection, 4 different registry locations all need to work together:

1. Service Set Identifiers (SSIDs):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Profiles
(This stores the SSIDs of the wireless access points that have been connected to and appears to be the most usual location for corrupted entries.)
From your experience/tests, this doesn't appear to be a factor.

2. Network Interface Cards (NICs):
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Adapters
(This stores a GUID and linked IP config info for each of the NICs - ethernet, wireless, bluetooth, NFC, loopbacks, etc.)

3. Signatures > Unmanaged:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Signatures\Unmanaged
(This stores the description and MAC address of access points that have been connected to, e.g. your router.)
From your experience/tests, this doesn't appear to be a factor as both routers (ISP and Starlink) work with 5GHz band.

4. TCPIP > Parameters > Interfaces:
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\
(This stores the DHCP info, e.g. IP address/subnet mask/name/servername - and DNS info, i.e. primary/secondary IP addresses.)
From your experience/tests, this could be a factor, even though both DHCP and DNS work with 5GHz band.

Your issues appear most likely to be 2 and/or 4 above, both linked closely to IP configuration for the 2.4GHz radio band (so I suspect VPN usage may possibly be a factor).

Your troubleshooting so far is well thought out but hasn't yet looked at the TCP/IP protocol's 'stack' (or 'layers').

For a start, I would first make sure VPN (and any third-party AV/firewall) was disabled then reboot and carry out a Network Reset to wipe out/refresh the TCP/IP protocol stacks for each network adapter. (The alternative is to go into the registry and remove the appropriate entries for just the 2.4GHz adapter.)

Hope this helps...

RickC said:

Your issues appear most likely to be 2 and/or 4 above, both linked closely to IP configuration for the 2.4GHz radio band (so I suspect VPN usage may possibly be a factor).

Your troubleshooting so far is well thought out but hasn't yet looked at the TCP/IP protocol's 'stack' (or 'layers').

For a start, I would first make sure VPN (and any third-party AV/firewall) was disabled then reboot and carry out a Network Reset to wipe out/refresh the TCP/IP protocol stacks for each network adapter. (The alternative is to go into the registry and remove the appropriate entries for just the 2.4GHz adapter.)

Hope this helps...

Thank you so much for the great info. I knew I would forget at least one of the things I'd tried and a Network Reset was it �� But I don't recall if I did it before or after I uninstalled my VPN. So, I uninstalled it again and did the Network Reset - still no luck connecting to 2.4GHz. So, I now need to try your second suggestion of removing the entries for the 2.4GHz adapter but can you please tell me how I identify them in the list of entries? I can't see anything that's specifically says 2.4GHz - not that I was really expecting that's what they would be called.

kiwichick said:

So, I now need to try your second suggestion of removing the entries for the 2.4GHz adapter but can you please tell me how I identify them in the list of entries? I can't see anything that's specifically says 2.4GHz - not that I was really expecting that's what they would be called.

I've just checked what you had already tried and see 3) Uninstall the Adapter Driver. Reboot PC for it to reinstall. I assume you did this via Device Manager? This has the effect of removing the network entry from the registry which is what I was going to suggest manually, i.e. deleting the entry under:

Code:

HKLM\LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkCards

Try resetting the adapter's advanced properties.

1. Right-click on Start then choose Windows PowerShell (Admin).

2. When the PowerShell console opens, copy/paste or type Get-NetAdapter then press the ENTER/RETURN key:

This is just to check the name of the wifi adapter. It's usually WiFi (although I've also seen one named as Wi-Fi).

3. Next, copy/paste or type Reset-NetAdapterAdvancedProperty -Name "WiFi" -DisplayName "*" then press the ENTER/RETURN key. This will reset the wifi adapter's advanced properties, rewriting new values to the registry.

4. Reboot and try connecting using the 2.4GHz band.

BTW - Have you tried the Network Adapter troubleshooting tool? (Settings > Update & Security > Troubleshoot > Additional troubleshooters > Find and fix other problems > Network Adapter) It's not mentioned in your first post.
Hope this helps...

RickC said:

1. Right-click on Start then choose Windows PowerShell (Admin).

Just as a note, bear in mind that PowerShell only appears in that menu if it's been set to in Settings. By default it's Command Prompt that appears there

2. copy/paste or type Get-NetAdapter then press the ENTER/RETURN key.
3. copy/paste or type Reset-NetAdapterAdvancedProperty -Name "WiFi" -DisplayName "*" then press the ENTER/RETURN key. This will reset the wifi adapter's advanced properties, rewriting new values to the registry.
4. Reboot and try connecting using the 2.4GHz band.

This worked!!!!! And I didn't even need to reboot (although I did just to make sure nothing went wrong during the restart). Thank you so much for working through this with me

Glad it worked for you. It beats manually editing the registry.

The fact you didn't have to reboot suggests the problem was with your user profile, i.e. registry settings in HKEY_CURRENT_USER. I always suggest a reboot in case the problem is machine/system wide, i.e. HKEY_LOCAL_MACHINE which really needs a reboot so the hive can be loaded from scratch.

Thanks for posting back to let us know.

RickC said:

The fact you didn't have to reboot suggests the problem was with your user profile, i.e. registry settings in HKEY_CURRENT_USER. I always suggest a reboot in case the problem is machine/system wide, i.e. HKEY_LOCAL_MACHINE which really needs a reboot so the hive can be loaded from scratch.

That is good to know, thanks. I'll add it to the notes I made for if it happens again.

RickC said:

Glad it worked for you. It beats manually editing the registry.

Unfortunately, it was short-lived. Back to not being able to connect to 2.4GHz networks. Tried the PowerShell net adapter reset again but no luck - not even after a PC restart.

kiwichick said:

Unfortunately, it was short-lived. Back to not being able to connect to 2.4GHz networks. Tried the PowerShell net adapter reset again but no luck - not even after a PC restart.

Try creating a new account and connecting again. If successful then this suggests a user profile issue. If not successful then this suggests a machine-wide issue.

Hope this helps...