java.lang.NoClassDefFoundError

I'm sorry to bother with so newbie questions but it is really annoyoing
me!

I have the quintessential error of:

Exception in thread "main" java.lang.NoClassDefFoundError:
ClassName/class

The directory i'm using is:

C:\work\java

I'm using Windows XP and my CLASSPATH has these values:

..;C:\work\java;

Is there something else I'm missing!

Thank you very much!

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