The second Tuesday of the month is here, and Microsoft's Lincoln's Birthday present is no less than eleven patches, six marked "critical" and five "important." One of the patches affects only Windows Vista users. The complete details of the eleven patches is available from the Microsoft TechNet site. Visit Windows Update to check whether your computer is patched, especially if you have Automatic Updates turned off. Remember to do this using Internet Explorer; Firefox or other browsers won't work with the Windows Update site.
The anticipated Service Pack 1 for Vista isn't available - officially - yet. It's expected in March. Reports from Windows news site WinBeta suggests that it's available now, but it's probably best to wait for the offical release date to avoid problems.
Apple also updated Mac OS X to version 10.5.2 yesterday. If you're using the third most popular operating system (after XP and the intrepid Vista users), you can find the updates here or by checking for software updates under the Apple menu.