...
Accessing Your Products Through Email
https://www.stardock.com/support/productkeyretrieval
While this page will work for both account holders and Guest Checkout purchase, the below is the only way a Guest Checkout purchase can retrieve their products and keys at a later date. When you enter an address that was used to make a purchase, an email will be sent to that address with the download links and keys for the products. To retrieve them, enter the email you supplied at the time of purchase here.
...
Accessing Your Products Through Your Stardock Account
...