The certificate's validity period or PC time is incorrect.
A certificate expiration warning will be displayed and secure access will be blocked.
Make sure your PC date, time, and time zone are correct.
If it is checked and resolved from above, you do not need to proceed to the next step.
A certificate expiration warning will be displayed and secure access will be blocked.
Difficulty Easy · Estimated time 5 minutes
Check points: Record the error code, when it occurred, and any recent changes.
The certificate's validity period or PC time is incorrect.
Difficulty Moderate · Estimated time 10~30 minutes
Check points: After modifying the date, check whether the certificate warning disappears.
When troubleshooting a computer that suddenly fails to connect to the Internet, it is important to rule out the causes one at a time. Based on the “No Internet” symptom, check the router/modem or ISP problem and the network adapter/IP/DNS settings, then proceed to the next step. Compare with other devices and wired connections to narrow down where the problem occurs: PC, router, or ISP.
Among Internet problems, the “Wi-Fi connected but no Internet” symptom may be related to the router’s Internet line or DHCP/DNS problems. Check the wireless adapter status, saved profiles, router/signal quality, and driver in order.
Content review date: 2026-10-07