Uncheck Excel's Ignore other applications' DDE and you're done!
You double-click an attachment in Outlook – or Thunderbird – or any mail client or third-party client, for that matter – and you can’t open the file in Office (in my case Excel 2007, but this works for Excel 2003 as well).
But instead of the file, you get a notification telling you that Windows cannot find “filename“. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button and then click search.
Fear not – there’s hope. (more…)