If you run into an issue where you are unable to download or save certificates using Internet Explorer 9 (IE 9) and the Certificate Authority Web Enrollment service of a certification authority, you should be sure to disable the enhanced security option of Internet Explorer. See TechNet Wiki article : http://social.technet.microsoft.com/wiki/contents/articles/you-cannot-download-ca-certi… for more details.
© Microsoft. This article was originally published by Microsoft's Core Infrastructure and Security Blog. You can find the original article here.