Consider the following scenario. You try to download a certificate (.cer) file in Windows Internet Explorer 7 on a computer that is running Microsoft Windows Server 2003. In this scenario, the Open button does not appear in the File Download - Security Warning dialog box. Instead, the Find button appears.
If you save the certificate file to disk and then open the file, the file opens successfully.
This problem does not occur in Microsoft Internet Explorer 6. This problem also does not occur on computers that are running Windows XP, even if you use Internet Explorer 7.
To work around this problem, create a new file association for the certificate file as the original certificate file association, and then open the certificate file. After you create the new file association, the Open button appears in the File Download - Security Warning dialog box.