I think it detects the hard drive ID and if it detects a mismatch between the HDD ID it was registered with and the current HDD ID it squeals to be connected to the Cakewalk registration service and goes into Demo mode.
A while ago I upgraded my system drive and had this happen but I don't know if they changed the system at all.
Unless there's a final release (doubtful) which removes the need to connect to the registration service the only way to future-proof will be, ironically and illegally, to get a pirate copy which doesn't phone home.
The utter irony after being a loyal Cakewalk customer for a long time despite issues with the product down the years.