HTTP 404 – Website not found

The requested page does not exist or is not displayed at this address.

Do not factory-reset a router speculatively or indiscriminately disable Wi-Fi security or a firewall. Get permission before changing someone else’s network.

Check the link for typos.
Open the provider's homepage and search for the content there.
Save the new link for an old bookmark. Windows does not need to be repaired for this.

Test after each step and stop when the issue is solved. Checkmarks are not permanently saved.