I keep getting a site that partially comes up... http://www.aim.com/PointRollAds.htm?pid=6 it never opens completely but is constantly popping up while I am trying to do searches or playing games... what is it? And most importantly how do I stop it?

In Internet Explorer:
How to configure the Pop-up Blocker on a computer that is running Windows XP Service Pack 2 (http://support.microsoft.com/kb/843016)

In FireFox (which I use):
Pop-up blocker (http://support.mozilla.com/en-US/kb/Pop-up+blocker)