You don’t see this too often. Microsoft today released a security update (KB929123) for Windows Mail that fixes a remote execution vulnerability. They also released a Knowledge Base article explaining what to do if your Windows Mail doesn’t work right after installing the update. A fix for a fix?

As noted in the Security Bulletin, the update “changes the MHTML protocol handler in Windows so that it securely handles MHTML URLs in redirection scenarios and scenarios involving ambiguously typed content”. Presumably some web servers aren’t setup properly to handle the change, which may result in you being prompted by a dialog box that requests more input about how to continue when you’re viewing content from the site.

Here’s a case where Microsoft did a good job. They tested the update, knew it would have problems that presumably are unavoidable at the client level, and immediately made a Knowledge Base article available (it’s even referenced in the Security Bulletin) with a resolution to the issue. The down side to this is that if you are having problems with this, you’ll need to get the server administrator for the site you’re accessing to fix the problem.