Be warned that some products , I'm pretty sure Melodyn is one, you need to de activate the original machine before you remove the old drive. But if you missed that they are generally good about taking pity and sending you a new activation code. Its just way easier to do it before hand.
Sonars activation system even though at first we questioned it, turns out to be one of the better ones.
As said all you need is command center and your log on.
If you still have your old drive I'd put it back in and de activate Melodyn and Adictive drums.
Also copy your Command Center download folder so you don't have to re download everything.
C/ Program DAta/Cakewalk/Command center.