If you plan to upgrade your operating system (i.e Win 7→Win 10, El Capitan→OS Sierra) we highly suggested that you leave Smaart activated and email us if you run into any problems after the upgrade.
Smaart should only be deactivated if the computer is going to be completely formatted*, if the operating system is being reinstalled completely*, or if the computer is going to be decommissioned from use.
Furthermore, if you plan to clone or migrate your system upon replacing the hard drive or moving to a new computer, please be sure to look at our article on Time Machine and Migration Software to prevent any issues with your license.
*Note for Window 10 Users: Windows 10 now contains a new feature called "Reset this PC" that reinstalls the operating system using a special Windows partition. Please note that because of the nature of Smaart's licensing system, deactivating prior to using this feature can cause problems, and so if you are going to "Reset this PC", leave Smaart activated. Unless you are installing Windows 10 fresh with a CD or USB and completely formatting the drive, Smaart should always remain activated. If you "Reset your PC" with Smaart activated and your machine ID changes (Error 523), please refer to our article on that here.