How can I block a specific domain using the hosts file?

Honestly, using the hosts file for blocking is becoming less effective these days. Just because a site looks like a regular DNS hostname doesn’t mean that’s how the client accesses it. Nowadays, sites might use SNI extensions or certain HTTP headers that bypass the hosts file. To properly block a website, consider using a transparent proxy or a secure web gateway that can analyze the traffic more effectively.

In your case, using Windows Firewall might be a good alternative. There's a tutorial out there that walks you through setting that up to block domains. It might be a more effective approach for what you're trying to accomplish.

If you're on Windows, you need to make sure you're editing the right hosts file in the right directory: C:WindowsSystem32driversetc. The format is simple: just add '127.0.0.1 badwebsitename.com' at the bottom. Remember, it shouldn't have an extension. That said, if it doesn’t work, you might want to check if there's a typo or try flushing your DNS.