A user had this issue, whereby they couldn’t open excel attachment from their OWA Webmail.
The files were being downloaded to their temporary files but then just would not open. If I opened outlook and then navigated to the file it worked.
The solution was this:
In Excel, click the Microsoft Office Button (in the top left)
Click Excel Options (at the bottom of the menu box on the right)
Click the Advanced category and then, under the General section, clear the Ignore other applications that use Dynamic Data Exchange (DDE) check box.
At the command promt navigate to: “c:\program files\microsoft office\office12″
- excel.exe /unregserver
- excel.exe /regserver