In case your registration key does not work anymore (for example, because the author has released a more recent version which may require a new key) or in case you lost your key due to a system crash etc, then you should contact the author of the relevant program directly. Send him an E-Mail, explaining the situation in one or two sentences and add your full address and - in case your E-Mail address has changed - provide your old E-Mail address, so that he can verify that you are an existing customer.
The author will send you a new registration key by E-Mail.
If you do not have the E-Mail-address of the author handy, you can find it on our support page.