This is a standard response when the browser gets no response from the web site you are visiting. More about 404 errors here; http://en.wikipedia.org/wiki/HTTP_404

If you get errors from sites like login pages, then as those sites are normally 'secure sites' there may be a problem with your security settings. You don't say which browser you are using, but if it is Internet Explorer try this;

In IE, goto Tools > Internet Options, then the Advanced tab. Scroll down to Security, then look for the "Use SSL" options.

Make sure the settings are as follows;

Use SSL 2.0 - Not selected
Use SSL 30 - Selected
Use TLS 1.0 - Selected
Use TLS 1.1 - Not selected
Use TLS 1.2 - Not selected.

If you changed any, click Apply then OK and test.

Mark