We've touched on the impending demise of XP Service Pack 2 (SP2) on a couple of occasions in the past week or so, and if you were still caught off guard today by Microsoft ending support, then extend your leg and swing it back as far and as fast as possible, with the goal being to kick yourself in your own ass for failing to pay attention.
Whether you were ready for it or not, what happens now? For starters, Microsoft will stop sending out updates and security patches for the now-defunct version of Windows, leaving XP SP2 users vulnerable in a number of areas, including IE, WMP, and Outlook Express.
You do have some options , however, the most obvious one being to upgrade to SP3. If for whatever reason that's not an option and you're simply stuck on XP SP2, you can make the best of a bad situation by first and foremost getting rid of IE. It doesn't matter what version of Microsoft's popular browser you're running, you won't be receiving updates. Instead, consider (strongly) switching to any of the alternatives, such as Firefox, Chrome, Safari, or Opera, all of which will continue kicking out updates.
Other steps you can take: update other programs, install AV software (if you haven't already), keep your firewall running, and cross your fingers.