Start → Whisker → Whisker Server
The WhiskerServer program must be running at all times when you wish to use the operant chambers. It is this program that actually communicates with the hardware.
However, you almost never need to interact with the server while it is running. It can provide you with a great deal of information about what's going on within your system, and can be very helpful for wiring up the system, testing devices and debugging client programs, but in day-to-day operation you can simply minimize it and forget it. (If you try to close the server while tasks are running, thus aborting any ongoing tasks, it will complain vociferously so you don't do it by accident.)