You cannot switch from Italian to English unless you obtain an English installer. If you have already obtained an English installer and wish to use English in the future, that's fine. 

However we do apologize for not having Italian ready the last time. A lot of small problems collided together to create that problem only for the Italian version (we had patchers available for all the other regions). I don't expect that problem to happen again, but it's up to you if you want to keep running Italian or switch to English.