Since the Wi-Fi adapter was already replaced and the troubleshooter reports DNS failure, follow this order to isolate whether the problem is Wi-Fi, TCP/IP, DHCP, DNS, or proxy related:
- Check whether the same network works on another device.
- Try the same Wi-Fi on a phone or another laptop.
- If other devices connect normally, the issue is likely on the PC.
- Run the built-in network troubleshooter.
- In Windows 10, go to Start > Settings > Network and Internet > Status.
- Select Network troubleshooter and complete the prompts.
- Reset the network stack from an elevated Command Prompt.
- Select Search, type command prompt, then choose Run as administrator.
- Run these commands in order:
netsh winsock reset netsh int ip reset ipconfig /release ipconfig /renew ipconfig /flushdns - Then restart the PC.
- Check for a bad IP address.
- Open Command Prompt as administrator.
- Check the IP address.
- If it looks like 169.254.x.x, Windows is not getting an address from the router.
- In that case, verify DHCP is enabled on the router.
- Check proxy settings.
- Go to Settings > Network & Internet > Proxy.
- Turn off any manual proxy settings.
- Verify the DNS server and test reachability.
- In Command Prompt as administrator, run:
ipconfig /all | findstr /c:"DNS Servers" - Note the DNS server address shown.
- Then run:
ping <DNS server address> - If the PC has a valid IP address but cannot ping the DNS server, change the DNS server to a different address and test again.
- In Command Prompt as administrator, run:
- If the problem started recently, reinstall the network adapter driver cleanly.
- Warning: uninstalling the adapter can temporarily remove network access until Windows reinstalls the driver.
- Open Device Manager.
- Expand Network adapters.
- Right-click the active network adapter and select Uninstall device.
- If available, check Attempt to remove the driver for this device.
- Restart the PC so Windows reinstalls the adapter.
- If Windows does not reinstall it correctly, install the backup driver from the PC manufacturer.
Because both the original wireless card and a replacement card show the same behavior, the most likely areas to check first are the Windows network stack, IP assignment, proxy settings, and DNS server reachability rather than the Wi-Fi hardware itself.