USB portable licenses - Licenses are assigned to a Keysight USB memory stick (dongle). Licenses are portable from one instrument to the next via the USB stick. Once the licensed USB stick is removed from an instrument, the licenses are no longer available (deactivated) on that instrument. To reactivate, re-insert the licensed USB stick. For Keysight-provided E8900-D10 USB sticks, you need to download Licensing USB driver.