If you are still on Windows XP SP2 with Internet Explorer (IE) 6, and you install the security update announced in MS07-069, then you may just have lost your ability to surf much of the web with IE. Apparently that combination causes IE to crash when you go to a web site, according to Microsoft Knowledge Base article 946627 and a blog post on the IE blog. The exact cause appears to still be under investigation. The signature of the crash, however, is shown in this picture:

The fix is to set a registry key. However, most home users would probably struggle with that, and enterprises, trying to figure out how to roll that fix out to 50,000 desktops would probably not be enjoying themselves tremendously either. In an attempt to help out I wrapped the required registry key in a Windows Installer program, attached to this post. The installer only sets the registry key. However, for a home user it is much simpler to double-click on an installer than navigating through the registry. For an enterprise, since it is an MSI file, it can be deployed with Group Policy to all affected computers. The best part is that it is completely uninstallable through Add/Remove Programs.

Hopefully this will help someone.

Read the complete post at http://msinfluentials.com/blogs/jesper/archive/2007/12/19/internet-explorer-6-crashes-after-you-install-security-update-942615-on-a-computer-that-is-running-windows-xp-service-pack-2.aspx