You can block some websites from opening on your computer using this trick.
step1: Type this%windir%\system32\drivers\etc in the run (WIN + R) or navigate to C:\Windows\System32\drivers\etc
step2: open notepad from start menu by typing notepad and running it as an administrator and then Open the hosts file by navigating to C:\Windows\System32\drivers\etc.
step3: Now if you want to block a site. say facebook or google for an example. Then type these lines. Locate the line “127.0.0.1 localhost” or “::1 localhost.” Put your cursor at the end of whichever line is lowest down.
step 4: Press “Enter” to create a new line.
step 5: Type in whichever website or websites you wish to block. You can add any site, but you’ll need to preface it with “127.0.0.1”. To block the website reddit.com for example, just type in “127.0.0.1” followed by a single space, followed by “reddit.com”. Add all of the site’s domains, especially mobile domains, on new lines. Your computer might block “www.facebook.com”, but not “m.facebook.com” if you’re not careful. This is an easy workaround for the experienced computer user.
step 6: Click “File -> Save” in order to save the hosts file. If a prompt comes up saying that you cannot save the file because you are not an administrator, you’ll need to change the administrator permissions to include you. To do this: Right-click on the hosts’ file, choose Properties -> Security and make sure all the boxes are checked in your user account. This should allow you to save the file as an admin. From the next time, the above sites will not open in your browser. To unblock, remove the above lines from the notepad (Note: This trick will work if your browser is not open.If your browser is open then close the browser and restart it.)