I recently wiped my hard drive and reinstalled VD2, but
the previous registration code isn't working for me. Do
I need to get a new one, and how do I go about it since
I've already registered 2 copies (one for work, one for home)?

You will probably need to re-register since the hard drive format has likely altered your System ID. In order to do this, you'll first have to [b]deactivate[/b] the old authorization for this machine. Do so, by going to the [b][url=http://www.nativeinstruments.de/index.php?id=register_us]Native Instruments Registration page[/url][/b]. Login to your account, and click the [b]Manage Registrations/Authorizations[/b] link. Here, you should see any and all NI software registrations (for each machine) that you have completed. When you see the two authcodes for your VDL2 registration, carefully (carefully) locate the one that corresponds to your machine with the wiped hard drive. If you're having trouble discerning which authcode is for which machine, reference the System ID number in the registration tool application (in your VDL2 folder). You may have to compare System IDs on each of your machines to be sure. Just be sure you don't deactivate your other machine.

Once you've successfully deactivated your old authorization, you'll be allowed to re-authorize this machine by running the registration tool again.