Sorry about replying in English. I can read Italian (somewhat), but I can't write it.
Apparently, your question is about some trouble printing photographs. Since this is completely unrelated to the Training and Certification forums, I suggest asking in an end-user suport forum. I presume that the HP desktop computer that you are using
is running some variation of the Windows operating system. This being the case, you may wish to ask in the relevant Windows forum at
Microsoft Answers. Here is the link to the index page:
http://social.answers.microsoft.com/Forums/en-US/group/WindowsAnswers
The preceding link is for the English forums. There is also a set of Italian forums:
http://social.answers.microsoft.com/Forums/it-IT/categories