Windows Says No Internet, but the Browser Works Through a Proxy
Check the connectivity probe separately from the browser session when a proxy login or different network route makes Windows report no internet access.
A working browser and a Windows “no internet” indicator can both be accurate observations. The browser's logged-in session is not the request Windows uses for connectivity assessment.
NCSI uses active and passive assessment, as Microsoft's overview explains. An active probe needs the expected response, not just a successful connection. The probe can use another destination, proxy policy or authentication context from the browser.
Inspect the relevant NCSI event and matching proxy request. Classify what the probe received:
- Its expected response.
- A proxy authentication challenge, such as 407.
- A captive-portal or other unexpected page.
- A connection failure.
An interactive browser login does not establish credentials for the background probe. A 407 in a proxy record identifies an authentication challenge; an unusual address in another field does not establish broadcasting or another network-level explanation without that field's definition.
Follow Microsoft's NCSI troubleshooting for the affected Windows release and actual probe destination. A historical endpoint copied from an old answer can exercise another path. If your organization operates the proxy, establish how approved connectivity checks should authenticate or pass through it. Disabling assessment can hide the symptom while leaving status-dependent applications with the same problem.