The location used for storing the InteractX activation varies by product and InteractX version.
InteractX 1.x uses software license and is stored as a series of files on the HMI's and development PC's hard drive.
InteractX 2.x can use either software and hardware license storage. Units that shipped with 2.x pre-installed were PX, EPX, and HPX. PX use software license. EPX and HPX panels use hardware license via EEPROM storage.
InteractX 3.x uses both software and hardware license. Units shipping with 3.x pre-installed were EPX, HPX, and IPX. All of these units shipped with hardware license via EEPROM storage.
USB hardware keys (INTX-KEY) could be used to transfer a software license to a hardware license storage. These keys are no longer available but were commonly used to make Development licenses portable between multiple PCs.
InteractX 4.x no longer offers a software-stored license and requires the use of a new "HASP" license key for development systems and EEPROM license for HMI. If it is an older HMI that does not support EEPROM license (or a white-box PC for runtime) the hardware key will be required.