A number of applications have updated recently. If you haven't installed the free FileHippo Update Checker, why not give it a try now? Here's the link: http://www.filehippo.com/updatechecker/
Noteable updates over the last week include Opera, Firefox, Thunderbird, RealPlayer, Yahoo! Messenger, Picasa, Avira Antivirus, Malwarebytes, SUPERAntiSpyware and my favorite, CCleaner. Click on each for the link to download the installer, or update from within the program, if available.
Microsoft has also released a critical update or two outside the normal schedule of the second Tuesday of the month. Install them when you see the prompt (lower right corner of your screen) or run Microsoft Update and install all the critical updates. Be sure to check the Optional Updates for Office updates and other necessary items.
I've been told by Hewlett Packard Tech Support engineers (HP/Compaq) that they prefer all updates be done through the HP Advisor. You should check HP for hardware driver updates, but Windows and Office updates still need to be done through Microsoft.