We wanted to write a blog post about an issue that some of you have reported to us, and has been discussed at some length in Exchange Forums also.
After you install Internet Explorer 9 on a computer that has Exchange 2010 or Exchange 2007 management tools installed, you might run into a situation where closing the Exchange Management Console (EMC) results in the following error:
You must close all dialog boxes before you can close Exchange Management Console
This might happen even if there are no property pages left opened that you can see. Please note here that not all of our customers who installed IE9 on a computer with Exchange management tools (server or workstation) have run into this problem.
Continue at source.
Technology Architect/Writer/MS Vendor
MCM: Exchange Server | MVP: Exchange Architecture