Once the Java runtime environment is installed, the WebStart application manager will detect when you attempt to download the program for the first time.

During the first installation, the WebStart installation manager will ask if you would like to integrate the program into your desktop environment -- You must answer Yes if you want to be able to run the program when you are not connected to the internet.

Afterwards, the main program window will appear.

If you chose the 'Yes' option for integrating to your Desktop, two icons will be added to your desktop. One will start the magcalc program and the other will open the Java Web Start Application Manager. The Application Manager enables you to control the Java-deployed applications on your computer -- however, in many cases you will never need to access this for only the MagCalc program.

One thing to note is that every time you start the MagCalc program it will attempt to check the USGS website for updates (for example, new model files). If you have a firewall installed, you may need to grant permission for java.exe, javac.exe and javaw.exe to access the internet to enable this.