With the latest iLok system, you no longer need the USB key as you can activate the license to your computer hard drive. As a benefit, you get three activations with your license so you can use your library on up to three machines at a time. You can also use the iLok USB key if you choose. Simply create a free account with iLok.com and that's all you need to use our libraries. We use the UVI engine and sample player and all authorized libraries for the UVI Workstation use the iLok copy protection system. It's a secure platform and allows easy use on more than one machine or as many as needed if using the USB key. Once the license is activated on your computer or iLok key, it stays and doesn't cause restrictions associated with challenge/response systems.