When you bought Virtual Drumline, you received a serial number. Depending on how you bought VDL, your serial number appeared on a label either inside the DVD case, or within the inside flap of the "Getting Started Guide." If you purchased VDL as a direct download, your serial number was emailed to you from Tapspace.
Your Virtual Drumline serial number is a very important part of your license to use the product, so we encourage you to keep it safe. It's also very important that you register your software right away, which will help us in retrieving your serial number should you accidentally misplace it. Lost serial numbers that haven't been registered are not recoverable.
If for some reason, you are having trouble locating your serial number and need it to reinstall the software, you may retrieve it by logging in to your user account on the Native Instruments registration page and selecting "view and manage authorizations." There, you will see a listing of any NI products you've registered.
Alternately, if you have the software installed on a machine already, simply launch the Service Center program, then go to the "Overview" section, and click on "show details" next to the product name. If you had successfully activated the software on this computer, you'll see your serial number here.
For further registration support, contact Native Instruments using their registration support page.