Here's the general rules for the Numerical Cloud activation:
1. Once you enter the activation code, you should never need to re-enter it again on the same computer. The first computer activated is considered the primary user.
Note: If activating on a second, or third computer; make sure to use the same Activation Code, Password, and e-mail from the first computer (i.e primary user).
2. Make sure you are using the command "Numerical Cloud Activation" located in menu: Help / Enter License Key / Numerical Cloud Activation...
Note: If you use the normal activate process (menu: Help / Enter License Key / Activate) it will not work, and state invalid activation code.
3. Make sure you are installing the software products to a folder with write permission.
4. You can always check on the status of your activation code here:
Thanks again, and please let me know if you have any other questions.