When you make a checkout from the e-store on the http://www.virtualroboticstoolkit.com website you'll receive an email notification containing a download link and one or more activation keys. Depending on the quantity of your order, your activation keys will be listed directly in the order itself or as a separate CSV attachment. You use the keys to fully unlock your copy of Virtual Robotics Toolkit.
Whenever you open an non-activated version of the Virtual Robotics Toolkit, you'll be asked to enter an activation key (see screenshot below). Enter the key exactly as it's displayed in the email and press the OK button to complete your activation.
Once activated, a seat from the license is allocated to the machine that the key is used on. How many seats your activation key contains depends on which version of the Virtual Robotics Toolkit you purchased. Presently there is the Team License which has 10 seats, and the Single License with 1 seat. Once all the seats are used up the activation key can no longer be used.
If you purchased a Team License and would like to install Virtual Robotics Toolkit on another computer, simply provide them with a copy of the VirtualRoboticsToolkit.exe file you downloaded from your activation email along with the activation key.