A DESCRIPTION OF THE PROBLEM :
The example has:
pb.directory("myDir");

but the argument should be a File, not a String.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
pb.directory(new File("myDir"));
ACTUAL -
pb.directory("myDir");

URL OF FAULTY DOCUMENTATION :
file:///C:/Program%20Files/Java/jdk1.5.0_03/docs/api/java/lang/ProcessBuilder.html
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