you complained that you are receiving error massage
java.lang.NoClassDefFoundError:... Ok you don't have
any problem  with your JAVA version or with any path or
classpath. leave it as it is. why you are receiving
this massage b'z JAVA is case sensitive may be you
have typed java xyz weather it might be java XYZ. so
type java XYZ only. and if possible please do one
thing when you create any new class, capitalize its
first digit Uppercase always. like Xyz or MyClass or
MyFirstApplet...

this will sure help you... if it dose leave massage
for me on java_official.