In the file org.apache.tools.ant.taskdefs.Execute.java, the static initializer tries to pick a CommandLauncher based on System.gerProperty("os.name"). However, under Java 1.4 and Windows XP, the property "os.name" that is returned is "Windows XP", not "Windows 2000" or "Windows NT". This results in a 16-bit CommandLauncher being used, rather than a 32-bit, and commands subsequently fail to execute properly (16-bit NTVDM error). I first ran into this bug when trying to use <property environment="myenv" />
*** This bug has been marked as a duplicate of 6456 ***