I have three licenses for NTFS. I have three Macs. NTFS quit working on my iMac. At first, I was baffled. However, recently Apple had to replace the logic board (what most of the world call a "motherboard"). I assume this deleted the registration as I assume it is tied to the logic board serial or other number. I cannot determine which NTFS serial numbers I used on the 3 computers as I know of no way to reveal that number once it has been registered. And I know of no way to unregister the iMac as NTFS claims it is not registered. So, I just bought another copy. I realize this is in the best interests of Paragon (more money) but I'm curious if I could get back the serial number so I can re-use it (if I ever buy another Mac).