I echo Olliâ€™s comments.
The Registration Key download link provide by SlySoft does not remain an active link for an indefinite period of time.
Perchance as requested SlySoft did you make a back up copy of your Registration Key on a floppy disk and/or CD disk. This following statement is what SlySoft sends to their customer when they receive their Registration Keys. 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€
If you failed to back up your Registrations Key you are goning to have to contact SlySoft and request replacement Registration Keys. This process will take some time.
You might be interested in viewing the below Forum Thread concerning lost Registration Keys.