Please share how did you activate DVDit Pro HD once installed on windows 7. I have the same problem.
Recently, after replacing the windows xp C drive (system drive) with a windows 7 C drive, I've reinstalled Roxio DVDIt 6.4 Pro HD from its original CD, which I bought 4 years ago, to this windows 7 computer. The installation was good, however; during the activation of DVDIt 6.4, I got an error message, “Unsuccessful Activation. There was a problem activating your product. This could be due to: Invalid product key".
Is this the compatibility problem between windows 7 and DVDIt 6.4? Please help. Thank you very much in advance.