How to activate offline your serial number if the online activating does not work
Install PostworkShop and launch it. Copy your serial number in the box and press : Activate serial number. Be sure to be OFFLINE from the Internet.
This box will appear. The buttons are not really visible, though it is a RETRY and a CANCEL. Press CANCEL (the button on the right).
The Product Activation window will appear. Select the correct option from the 3 possibilities (You can just leave the automatically checked first option) and press NEXT.
Click the link you are given: activate.esellerate.net
Reconnect your computer to the Internet. The eSellerate page will open in your browser with the Installation ID automatically filled in. Press SUBMIT.
Copy the Activation Key you are given at the bottom of the page - the long code with orange background on the image - , you can also email it yourself.
Paste the Activation Key (with one simply copy/paste in the A box, it will fill everything automatically). Press Activate.
PostworkShop has been successfully activated on your computer.
You're now ready to create!