Videos and Facebook Chat Stall my Browser

So I've got a relatively new laptop and it has been working fine ever since i got it until this past weekend. I don't know what happened but now whenever I try to open videos (youtube, embedded on facebook, etc.) or facebook chat, the browser does not respond. This only started happening after I got my free Windows 7 upgrade from HP. I've tried multiple browsers (Firefox, Chrome) and am currently using IE8 because it is the only browser that doesn't stall when on Facebook. All of my necessary plugins are installed and working, except whenever I go to the test site, it fails when the video attempts to play. I've put it off for awhile, and this is my attempt to be proactive. Please help. You're my only hope. :)