How can I inform which program to use to open a Docx when it doesn't show in my dropdown list in attachments?

Question

When I attempt to open a Docx type file Thunderbird is attempting to open the document with an old version of Office (2003). I have upgraded to (2013). I have followed the suggestions of going to Tools, Options and Attachments to assign which program should be used to open which type of item. Microsoft isn't even in the list at all. How do I fix this?

Answer 1

In Tools > Options > Attachments > incoming tab
delete the action for docx documents - located in the Action drop down selection.
It will remove it from the list.
* Then select email with docx attachment.
* Right click on attachment and select 'Open'
It will ask what to do
* Select 'Open With'
If TB does not select as default: MicroSoft Office Word
* click on drop down and select 'Other'
If MicroSoft Office Word is still not available:
* click on 'Browse' to locate the WINWORD.EXE file
If running Windows OS 32bit then it will be in this location :
* C:\Program Files\Microsoft Office\Office15\WINWORD.EXE
If running Windows OS 64bit then it will be in this location :
* C:\Program Files(86)\Microsoft Office\Office15\WINWORD.EXE
* Then click on click on 'Open'
* select: 'Do this automatically for files like this from now on' click on OK"