Microsoft has just released two updates as part of its November Patch Tuesday cycle. One of the updates will really only apply to a limited number of servers (specifically Windows DNS servers). The other update is pretty important for all users. It addresses a vulnerability in the way internet addresses are handled--meaning that someone could craft an address that would allow them to take over your computer. And this is a well known vulnerability that is already being exploited, so it is important to patch your computer as soon as you can.
For more information about patching and keeping your computers up to date, see my first Patch Tuesday blog entry.