Why doesn't my key work?
On version 3, when a new key is entered into the Control Panel “Key” page, the message “The software cannot be used on this machine”
is displayed. The old key is then returned to the “key” dialog.
The usual reason this happens is that the machine name is incorrect. Check that the name of the machine
is the same as the one in the license.
For more information about versions 4 onwards, please see Knowledge Base Article 0329 (see below)
Keywords:key invalid software cannot be used