Computer Experts! Technical question about IE6 settings and LANs

At home, we have three computers hooked up to an Ethernet network: two desktops and a laptop. They can all access a broadband Internet connection through a high-speed router, and the two desktops, at least, run Windows XP. The router has a firewall and all the computers are runnings some type of Norton Anti-Virus. On my computer, I’ve been browsing the Web without problems, but today, when I tried to access a web site which had worked fine before, I got the message “401 The web site is blocked by administrator.” (The web site in question is, in case you’re interested.) Problem is, I’m the administrator of my computer. Recently I downloaded Steam (to play Counter-Strike), Gamespy Arcade (for everything else), and WinMX (to share music I create at my karaoke machine), and I’m wondering if one of these changed Internet Explorer settings somehow.

Anyone have any ideas? Because I’m baffled.

Check if you have any parental controls activated by your browser, computer, router, or even ISP. That’s what the problem sounds like to me anyway.