MrLarone is right, but if it dosn't let you do that than email stardock or visit their tech. support
https://esupport.stardock.com/
https://esupport.stardock.com/index.php?_m=downloads&_a=view
If you do the second one, then enter the eamil and password you used to buy, and you should be able to download it... other than that, i think there's only one other possability, and thats if they sent it by mail. The mail man delivered it to the wrong house, and your neighbors that might not like you kept it (federal offence) or the mailman stole it (federal offence) lol
hope i helped!