SilentPrint has been re-installed but won't work with the licence key. This refers to version 2 software.
The Installation ID (previously registration code) is used to create your licence key. They are linked and the licence key that is created will only work with that activation code. This is done in order to prevent licence piracy.
If you suffer a disk crash or similar and you have to re-install SilentPrint the new installation will have a new Installation ID created during installation . This means your licence key (based on the original Installation ID ) will no longer work. In order to get SilentPrint working again a new licence key must be created from this new Installation ID so the link between the licence and the Installation ID is then restored.
Further information on how to obtain a replacement licence key in such circumstances is included in the following knowledge base article...