Error message: The product appears to be validated but the serial number or machine SID doesn't match

Hi,

I'm getting the above message (in the title) when I try to run my copy of GalCiv2.  

     The situation was that on my old hard-drive I had installated the Totalgamingnetwork and a version of Stardock Central over a year ago.

Since then, that hard-drive is no longer my central hard-drive, the CPU/mobo are not the same, and that SDC isn't the main one I use.  I just did a fresh install of Stardock Central on my new boot drive.  It does not appear to see the old hard-drive where I have a full directory of Totalgaming network games, directory structure completely unmodified.

So I'm guessing the problem is the machine serial ID number needs to be updated.  Is that possible, or must I go through the process of re-downloading all my games again?  If I have to do that, if I choose archive option in SDC this time, will it avoid the re-downloading part, if I modify my computer further in the future?