Read here to learn how to properly use 4-probes Teethan
Connect Teethan's USB receiver to a free USB port before starting Teethan's software.
Issues here? Read this article
Start Teethan and turn on the probes by swiping the probe onto the magnet of the chargin station, indicated by Swipe for activation. Bare in mind to swipe the thinner part of the probe, indicated by the Teethan logo.
To be sure that the probes have been turned on correctly, check if they blink with a white-colored LED; after some seconds, via software, the icons 
indicating each probe will turn on as well, letting you know that the USB receiver has recognized the probes.
Icons will show, also, the battery state of each probe.
If probes are not sufficiently charged, Teethan Tests won't be available.
If you have issues turning on the probes, read here.
If you have trouble with probes connection via software, read here.
When probes are all connected and well charged, the fun begins!