I was getting those all the time until I realized that I was not running a firewall. DO NOT, I repeat DO NOT, click on any of those. They are not official messages. They are popups advertising they pop-up blocking software, or worse. I find it funny how they are trying to "advertise", and don't trust any of them. Get yourself a firewall or up the security if you already have one. A hardware firewall is the best, but Windows XP has a pretty decent one and there is another on you can download that is good, but I can't remember it off the top of my head right now. Oh, and I was using Spybot to try to combat these things and it didn't do much. It helped a little, but they would be back as prolific as ever in a couple days. I think they try to ping your computer to see if you're online and then activate the popup that way.