How to Block Websites in Windows 8′s Hosts File
 

Windows 8 takes a new approach to the hosts file by default – it won’t allow you to block Facebook and other websites by modifying your hosts file. Luckily, there’s a way to bypass this restriction.

When you add certain website addresses to Windows 8’s hosts file, Windows 8 will automatically remove them, effectively ignoring your changes. Microsoft isn’t just doing this to annoy us – there’s a good reason for it.

http://www.howtogeek.com/122404/how-...8s-hosts-file/