Hi elenalee,
In order for ContourCAM to work (indeed be installed) you need a version of DesignCAD 3D MAX v. 14 - 21.
Once that's installed, you can install and work with ContourCAM (please follow instructions for installation with download).
To use it, it's a good idea to read chapters 1, 7 and 8 of the ContourCAM User's Guide, which you'll find, when you go Start > All Programs > ContourCAM.
It's pretty easy to use. For instance if you want to cut something, you draw the item you want to cut in DesignCAD 3D MAX and snap a number to the point you want to start at and save your file. Then you open the ContourCAM menu, select cutting and enter your parameters, generate your G-code and send it to you CNC cutter.
With the Magic CAD/CAM Sweet (DesignCAD 3D MAX and ContourCAM bundled together) you can bore, cut, engrave, mill, and turn, depending on your CNC machine.
If you go to
http://www.magiccadcam.com, you can download trial copies of both programs from Demos.
Hope this helps.