If you encounter problems with running junit test in Eclipse and you get following exception:

Exception occurred executing command line.
Cannot run program "C:\Program Files\Java\jdk1.7.0\bin\javaw.exe" (in directory "C:\......"):
CreateProcess error=206, The filename or extension is too long

please download patch for Eclipse.

For Eclipse Juno and newer:
https://bugs.eclipse.org/bugs/attachment.cgi?id=216593
For older Eclipse:
https://bugs.eclipse.org/bugs/attachment.cgi?id=219900

After download back up existing eclipse/plugins/org.eclipse.jdt.launching_3.*.jar
Copy and paste classes in the patch to org.eclipse.jdt.launching JAR (replace existing files).
Restart Eclipse.

For me it worked.

In bug report Bug 327193 it is considered fixed, but it happen to me recently with Eclipse Kepler 4.3.2.