Welcome to Gaia! ::

I'm trying to run a java program I compiled using the command prompt. This worked on my school computer, but it isn't on my home one. I go where the .class file is located then type:
java ClassName [ENTER]
and it says:


So, can anyone give me some pointers? I've looked this up on other online forums, and people keep mentioning "paths" and "variables" and other things I don't understand yet (I just started an Intro to Programming class, so I'm just getting the hang of it!) So if the solution involves something a newbie programmer may not understand, please be kind enough to walk me through it! Thanks! I appreciate it!