You are probably using the wrong software. When you get CNCmotion, you actually get two programs. CNCmotion; which is used to simulate machining on the students computers, and CNCbase, which is used to actually runon the machine attached to the computer. Because it is attached, CNCbase does not have a 3D simulation component.
Look in the upper corner of the software (see below) and if it says CNCbase, remove it and install CNCmotion.