Step 1 : Click Start -> All Programs -> Accessories, right-click on the Notepad, and then click Run as administrator. The start menu might be slightly different with yours as I have change it.
Step 2 : Open the hosts file by navigate to C:\Windows\System32\drivers\etc path, then select All Files option to display the files on etc folder.
Step 3 : Once you have select All Files, you will see that is about 5 files appear on Window. Click on the hosts file, then hit Open button.
Step 4 : Add new entry of website that you need to block, click save and exit. This time when you save your changes, there will not be an access-denied message.
Now, you can restart your computer. The websites that you have blocked will not be accessible anymore.
