You can purchase a license for Quanto from the Natara website at http://www.natara.com/quanto/purchase.cfm.
After purchasing a license, you will receive a registration number by email (usually within the hour). Follow the instructions in the email to enter your registration number in the registration number dialog.
Lost Registration Numbers
Visit the Natara web site www.natara.com to request your registration number if you misplace it.
HotSync User Name Change
If you change your HotSync User name you can continue to use the original registration code by entering the original HotSync User name in the User field.