ClassNotFoundException error HELLLPP!!!!!?

[aricsson]

so ive searched up all on the subject and i dont understand anything ( im only 15) ! java doesnt work and ive unstalled and reinstalled ALOT of times does anyone know how to fix this ? and explain it step by step and simply

[I-75]

You need to give us more detail. Are you writing a Java program or running a Java program? Java is not able to find the class. Most likely you have a classpath problem. Possible root cause

1. Directory problem, coping files into the wrong directories or missing files
2. Complie problem