How do some websites BLOCK some users from their sites?

Looking to block certain websites from certain users on Windows Xp..?

• Is there a way to block certain websites from select users and not all of them? I don't want to have to fumble around with settings everytime I get on the computer to go to aol or yahoo. I only want my kid going to websites where he can look things up that are educational. I'd prefer to use IPSec or any of the other programs that come semi-installed in windows. I have googled this question and I cannot find the answer.

• Answer:

  I use the HOSTS file to block certain websites...mostly ad servers, like: http://pgl.yoyo.org/as/serverlist.php?showintro=0;hostformat=hosts This reduces clutter on webpages. ANY website can be blocked. http://www.ehow.com/how_7309117_can-account-entering-certain-websites_.html Guest accounts need administrator password to alter HOSTS. HOSTS file is on every windows, unix, linux, and mac. A great way to work with HOSTS file(on windows): http://www.funkytoad.com/index.php?option=com_content&id=13