Hi, I’m B. Ashok, the Product Unit Manager for Web Development Tools. As mentioned in my earlier post last summer, we have removed the DHTML Editing Control from Windows Vista as part of making the operating system more secure.
One application that used the DHTML Editing Control in the past was OWA (Outlook Web Access). We have issued a required update to both Exchange 2000 and 2003 that enables OWA support for IE7 in Windows Vista. However if your server does not have this update applied, you may experience the inability to compose and edit e-mail messages on OWA when running IE7 in Windows Vista. When this happens, you will see a red ‘x’ in place of your e-mail message body.
The Exchange team has a good blog post which explains the issue in more detail, and describes how to update your Exchange 2000/2003 server to remedy this issue. The update does not require a reboot of the Exchange server and will fully enable OWA to work for clients using IE7 in Windows Vista. If you run into this problem, we highly recommend that you contact your Exchange 2000/2003 administrator to make sure they have installed this update.
One other item to note is that the update referenced in this post, was re-released on Feb 2007 to fix two additional issues:
If you are running into either of these two issues, installing the current version of the update should fix the problem.
Hopefully this helps anyone using Windows Vista who may be experiencing this issue with OWA.
Edit: title correction