Error

Hello everybody,
Can anybody tell why the following error occurs while am trying to run the Client class from Command Prompt.

ERROR
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D:\PrintHello\printservice>java Client.class
Exception in thread "main" java.lang.NoClassDefFoundError: Client/class
Caused by: java.lang.ClassNotFoundException: Client.class
at java.net.URLClassLoader$1.run(URLClassLoader.java: 200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 06)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:276)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 51)
at java.lang.ClassLoader.loadClassInternal(ClassLoade r.java:319)