Dear harlan4096,
Many thanks for your kind reply!
I had to create a new account in order to renew my Antivirus licence. There was also a problem with automatic activation. But, as soon as I did all that, I found my old password. Luckily, I had it written somewhere in the papers. Now, I am able to cancel the old subscription, and delete the old account.
Many thanks again! Kind Regards,
Zeljka