Activation - back-up hard drive? Norton 360

Hi.  The hard drive in my laptop is failing.  I have a Norton 360 licence for 3 installs - all 3 are used on 3 different laptops.  As my hard drive is probably on the way out, I bought a new hard drive and installed Windows and all my programs as a back-up so I can just swap the drive if the old drive fails (long story short, can't clone the old drive - Sony is picky and needed to use recovery disks).

So I now have two hard drives with all my software on, for the same computer.  If I install Norton 360 on the new drive and activate it, will it recognise it as the same computer?  Or will it see it as an extra licence needed?  Obviously I won't be using both drives at the same time, so only need one licence for that laptop.

I wasn't sure if the licence is for the laptop, or for the hard drive.  Thanks!