You have installed Java, downloaded the Ocelet Modelling Platform from the web site, unzipped and saved the folder. And when you try to run the OMP it doesn't work.
Most of the time this happens when your version of Java is not right for the version of Ocelet you downloaded.
Check again that :
if you have a 32 bit version of Java you also have a 32 bit version of Ocelet
if you have a 64 bit version of Java you also have a 64 bit version of Ocelet