How do you block youtube by using a router?

I'm pretty sure this will work:

Go to your home drive (C: unless you have changed it), Windows, system32, drivers, etc.

now look for a file called hosts. make sure it is not host.ics. double click on it, and open it with notepad. scroll down to the line with 127.0.0.1 localhost on it. then after that line, type in:

127.0.0.1(tab)www.YouTube.com

then save out of the file and try to open the website in your browser.

If that doesn't work, try doing it with the ip address instead of the url.

Hope that helps.