This isn't new, but we're simply posting this here as a quick directed link to the NI page which allows you to:

1) Change your address data or username
2) Change your password
3) Retrieve a forgotten password
4) View and manage your NI registrations

Here's the link:
https://www.native-instruments.com/index.php?id=regsuppfrm

i was having an issue with this i was hoping you could help me. i know that this is usually dealt with through native instruments, but I've recently had to format my computer and i was able to put the serial number into native instruments cause it was on my account still, but it prompts me for an activation code which i don't know how to get. virtual drumline doesn't seem to be listed as a product on native instruments in the support page you posted here, so I'm having trouble getting the help i need from there. thanks! :D

If you have already registered Virtual Drumline with Native Instruments, you'll use your NI account  to log into the NI website (usually it's your email address and the password you created when setting up your NI account).

If you're authorizing VDL on your newly formatted computer, do so by using the Service Center program. You can download the latest version of Service Center here.
http://www.nativeinstruments.de/index.php?id=freeupdates#NI_Service_Center