Microsoft is posting a new update for Windows today. This is a cumulative security update for Internet Explorer. Users should visit Windows Update to get the latest updates. Here's some more information:
Windows Security Update for December 2004
The Microsoft Windows security update for December 2004 is a cumulative security update that resolves a newly discovered issue in Microsoft Internet Explorer 6 Service Pack 1 (SP1), a component of Windows. If you have any of the software listed on this page installed on your computer, you should visit the Windows Update Web site to install the related update.