For purchases made directly from Stardock, you can get your key(s) from here:
https://www.stardock.com/support/productkeyretrieval
Activation Via In-app Prompt
The images in this example will show Fences but the dialogue and the procedure will look and be the same regardless of the product. If your activation method does not look like any of the images below, please click here.
To activate, click the 'Enter Product Key' button.
Enter in the product key you received and your email address and click 'Activate'. If you do not have your product key, you can go here for instructions on how to retrieve it.
If you already have an account and have activated the product previously, you can click the 'Stardock Account' option at the bottom to activate with your Stardock account credentials instead.
If the activation is successful, you will see a dialog stating so.
Offline Activation
If there is a problem activating, you may see the following:
In this case, your Internet connection may be functioning but your ability to connect to the activation server may be blocked. Click the 'Offline Activation' button to proceed.
Click 'Save Activation Request'. A dialog will prompt you to save the .req file. Save it to a location of your choosing. You will then see the following:
If your machine is able to access http://activate.stardock.com/ you can go there and upload the .req file which will give you a .resp file to save to your computer. You can then click the 'Select Activation Response' button to browse to where the .resp file is saved. This will complete the activation.
If you are not able to access http://activate.stardock.com/ from the machine you are activating on, you will need to bring the .req file to a machine that has internet and complete the process there and then bring the .resp back to the machine you wish to activate on. The .resp file can also be loaded using the 'select offline file' option as seen on the initial activation screen in the second image at the top of this webpage above.
If you receive any errors trying to upload the req file or download the resp file (404 errors), please try another web browser like Internet Explorer, Chrome, Edge, or Firefox
Troublshooting Activation Issues
Please see:
https://support.stardock.com/space/SHC/1350696976/Activation+Troubleshooting