Hello,
Sorry to hear you are having issues. Need to know more specific information. Is the popup message asking for activation, mentioned that you just need to activate or you need to deactivate other system before activating on this system?
For the first it is just that you are not activated and for the second, it show that you have maximize out your activation. For the first one. Please try this steps : https://forums.stardock.com/486311/accounts-and-activation-support-faq#keepsaskingactivation.
For the second case, you will need to use this steps to review and manage your activation: https://forums.stardock.com/486311/accounts-and-activation-support-faq#reviewactivations
Note: Do know that if you running dual boot system. You will need to use up two license slots for these two systems.
Thank you.
Basj,
Stardock Community Assistant.