Please reinstall Silverstack on your old computer and re-activate the software. After Silverstack is activated, please go to the license menu and deactivate your license from the computer. You can now activate the license on another computer. If this is not possible, please send an email to support@pomfort.com.
You can check whether your license is activated and on which computer it is on, by logging in to your Pomfort Account. More information about the Pomfort Account can be found here.