Windows uses the Registry to store information about every piece of software and hardware installed in your computer. If you change information in the registry, the way Windows interacts with software and hardware differently as well. While not designed to do so, the Windows Registry can act as a website blocker as well. Using the Registry to block certain websites is quick and effective. However, changing the Registry can also harm your computer if you're not very careful.
Press "Windows-R," type "regedit" in the Run box and press "Enter."
Using the folder structure on the left side, navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap\Domains. This is where Internet Explorer looks for blocked domains. "Domain" is another word for "website."
Click on the "Domains" folder. Go to "Edit," "New," "Key," and type in the domain name of the website you'd like to block (for example, "TheWebsite.com") as the name of the new folder. Press "Enter."
Go to "Edit," "New," "DWORD (32-bit) Value." Type in "*" (without quotes) as the name, and press Enter. This makes sure that any sub-domain (for example, bla-bla.TheWebsite.com) is also blocked.
Go to "Edit," "Modify," type in "4" for the value data and click "OK". The value of 4 here tells the browser that the website is forbidden.
Repeat Steps 3 to 5 if you'd like to add more websites.
Open Internet Explorer and navigate to one of the blocked sites. It should tell you the site is restricted.
If you'd like an easier way to block websites, simply add sites to the Restricted Zone by going to "Tools," "Internet Options" and clicking the "Security" tab. You can then type in the sites you'd like to block by clicking the "Sites" button on the right.