Ciao
intanto ho trovato una soluzione.

Copincollo dal forum sul quale ho trovato questo post:

if you are referring to the issue of double-clicking file opens Word, but not the Word document, and the user can open Word documents by using Word's File -> Open, then:

Go to the File Associations (Within Windows Explorer, Tools -> Folder Options -> File Types Tab)
Scroll to problem association (.doc and .docx)
Click 'Advanced'
Select Action 'Open' then click 'Edit'
Uncheck 'Use DDE'
Click 'OK' then 'OK' then 'OK'

Ha funzionato.
Ciao e grazie
Danielle