Hello Gedact8,
Based on a look at PACE's system, I see that you currently have a Hauptwerk Lite Edition subscription licence, which is currently activated to your iLok Cloud account.
Is that the licence you're referring to? Do you mean that you're just trying to set everything up on your new hard-drive to use that licence as before, via iLok Cloud? If so, then you don't need to activate anything, since it's already activate in your iLok Cloud account; in iLok License Manager you just need to go use 'File | Open Your Cloud Session' from the menu. Once you've done that, iLok License Manager and Hauptwerk will 'see' and use your existing Hauptwerk Lite Edition licence.
Note also that a subscription licence (such as your Hauptwerk Lite Edition licence) is equally valid for *all* v5+ Hauptwerk versions. Hence I would recommend installing Hauptwerk v6.0.1 ( viewtopic.php?f=10&t=19228 ) instead of v5. It has a lot of improvements over v5, and you're subscription is equally valid for v6, so you might as take advantage of it -- it wouldn't cost you anything additional.
Or do you mean that you're also trying to do something else, such as register a new/different licence, or move your existing Hauptwerk Lite Edition licence to an iLok dongle?