JUnit.org Resources for Test Driven Development

hi,
I have the same problem described a week ago, i cannot install JUnit on my system, i'm getting the same kind of error or exception message when i attempt to run the tests;

C:\junit3.8.1\junit3.8.1>java -cp junit.jar; . junit.textui.TestRunner junit.samples.AllTests

Exception in thread "main" java.lang.NoClassDefFoundError: /
Caused by: java.lang.ClassNotFoundException: .
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Could not find the main class: .. Program will exit.

So i'm curious, how can I fix that problem? because I also tried to reset the classpath var in the system properties by typing set classpath=%classpath%;C:\junit3.8.1\junit-3.8.1.jar; but without any luck!!!

Help!! lol

Thank you