Hi guys!
I cannot how grateful I'm for all for all the help you extend to me :)
I solved the issue by just by reinstalling the KSK on my desktop computer.
Indeed I have reboot my computer before but nothing happens.
Indeed, up to now, I have the free version of KSK so no licence key is needed.
Indeed, my computer was not showing up in MyDevices of MyKaspersky account.
All that said, I must say that in the past installation I was not able to use the same credentials. I can't explain why but even if it was the same user, the passwords weren't the same in the Windows app as it was in the MyKaspersky site. Even when I try to use the credentials of MyKasperky, the app rejected my attempts to connects with that password. Now that I have reinstalled the product both credentials are the same and my desktop computer is showing up in MyDevices.
Thanks!!!