If you choose to uninstall the Visualizer Professional the emWave PC version 1.x will continue to work with the original version of Visualizer it ships with.
However, if you choose to uninstall both emWave PC and the Visualizer, please uninstall the Visualizer first, then uninstall your emWave PC.
If you uninstalled the emWave PC first, you may have to reinstall it to then go ahead and uninstall the Visualizer Professional.