@ Dr Talk,
If you are unaware the download link for your Registration Key doesnâ€™t remain an active link for an indefinite period of time.
I hope you have done the prudent thing and made a back up copy of your Registration Key to a floppy disk and/or CD placed in a safe place.
The below is a direct quote from SlySoft ->
â€œPlease make a safety backup of your license key file on a floppy disk or a CD and keep it in a safe place - we cannot replace your license key, if you have lost it!â€