When you uninstall Photoshop CC does it resolve the issue? Have you tried it? If not try it.
Without the serial number you are not likely to get very far and we can't help you here because there is no official method of retrieving the serial number from Sony machines which came pre-installed with bundled software.
Perhaps, you can ask in the Photoshop forum if they know how to rectify this situation.
Thank you for your answer, mytaxsite.
I’ve already found the serial number, when I sign in, and went to My Adobe section.
Unfortunetly, it is not recognized by my Elements.
Is there somebody I can talk to or write to solve this problem?