No actions are taken when double click on an attachment in Thunderbird

This is a known problem and has been discussed in MozillaZine Knowledge Base (http://kb.mozillazine.org/Actions_for_attachment_file_types).

In summary, the following steps should be taken to solve this problem.

1. Make sure Thunderbird is NOT running.

3. Delete mimeTypes.rdf from hte Thunderbird profile folder.

In Windows XP, it is usually at C:\Documents and Settings\\Application Data\Thunderbird\Profiles\; In Vista and Windows 7, it is at C:\Users\\AppData\Roaming\Thunderbird\Profiles\\.

4. Restart Thunderbird. Now if you double click on an attachment, it should ask you which action you want to take.