The ViennaKey is a USB license control device (dongle) that is necessary to run any Vienna Instrument. This Syncrosoft protection device is not included in any Vienna Instrument product except for the Symphonic Cube.
One ViennaKey is needed for every computer that is running a Vienna Instrument. A single ViennaKey can be used for multiple Vienna Instrument Collections as long as they are on the same machine.
Licensing information can be moved from one ViennaKey to another, but the same Collection cannot exist on two keys at the same time. A Syncrosoft USB protection device from another company can also be used for a Vienna Instrument, but it won't run any Vienna Instrument demos.