>>FireFox may be enumerating and using the Windows registered file types stored in the Registry. There is some information at http://www.awitness.org/delphi_pascal_tutorial/source4/registry_associated_applications.html .
>>
>>You can also Google [windows registered file types enumerate].
>
>Thanks, Firefox returns "Microsoft Word 97 - 2003 Document" but in the Windows Registry, it's "Word.Document.8". So, I guess Firefox does not rely on the Windows Registry to return the registered file types known as. It probably has something on its own. In this case, the explanation is much better. So, this is the kind of enumeration I would like to obtain. I will keep looking for a list with most commonly used file type enumerations.
>
>BTW, while at it, I found a bug in Firefox. With the above type, this goes off the dialog as the text is too large.

When you look at HKEY_CLASSES_ROOT\.doc, the Default value is Word.Document.8. But then, as outlined in the first link I listed earlier, you have to chase down another key to get the friendly name. In this case you would go to HKEY_CLASSES_ROOT\Word.Document.8, and you see that the Default value is "Microsoft Office Word 97 - 2003 Document", which is the friendly name.

Windows itself also shows "Microsoft Office Word 97 - 2003 Document" in its list of registered file types, so it looks like FireFox is using the same mechanism Windows itself uses.