Well this trick is very simple and it goes this way.
1. Open MyComputer
2. Browse C: (or your Operating system drive)
3. Browse windows –>System32–>drivers–>etc
so the Location will be C:\WINDOWS\system32\drivers\etc
In the etc folder look for the file hosts
4. Open this file hosts with notepad.
5. Locate the line 127.0.0.1 localhost
6. To block www.google.com for example, just add this text under
7. Save the file.
In this way add any number of sites you want, however you will need to prefix it with “127.0.0.1″.
Note: This blocks the website from opening in any browser whether it is Mozilla Firefox or Internet Explorer.