You might have some form of DNS redirection malware. I would perform a scan with Malwarebytes in safe mode and let it clean any issues it finds.
I would also disable the DNS client service, then use CCleaner to clean the files AND registry. Reboot and test things out.
You can re-enable the DNS service at any time, but even better would be to set your entire network to use the fastest dns server found when running the tool attached. You could also set just your machine's network adapter to use the fastest dns, instead.
Otherwise, check on your proxy settings in Internet Explorer settings.