I found a bug in the Ant 1.5 on Windows 2003 expressing itself in ntvdm.exe 
exception:
************************************************************************
C:\WINDOWS\system32\ntvdm.exe
Error while setting up environment for the application. Choose "Close" to 
terminate the application.
************************************************************************
It happens when we source the current environment variables from the 
environment, rather than properties file, starting with 
<property environment="env"/>

Doing my research of the Ant 1.5 source code I established that while ant 1.5 
correctly reports Windows 2003 as an operating system being run in a verbose 
mode, when it's coming to choosing the executable for the command line, it 
wrongly picks command.com instead of cmd.exe.

I changed the logic of getProcEnvCommand() method in Execute.java to overcome 
this problem so that it will work with all systems it worked before, plus 
windows 2003.

I'll describe the change to the source code in getProcEnvCommand() method in 
Execute.java of Ant 1.5:
***************************************************************************
original code snippet with its author's comments (bug: the execution thread 
was testing "if" clause negatively and executing the code in "else" clause) 
***************************************************************************
...
else if (Os.isFamily("windows")) {
            // Determine if we're running under XP/2000/NT or 98/95
            if (!Os.isFamily("win9x")) {
                // Windows XP/2000/NT
                String[] cmd = {"cmd", "/c", "set" };
                return cmd;
            } else {
                // Windows 98/95
                String[] cmd = {"command.com", "/c", "set" };
                return cmd;
            }
...
******************************************************************************
new code snippet substituting the original one; the execution thread tests 
negatively the "if" clause and executes the "else" clause
******************************************************************************

 //IR debuggged code
        }else if (Os.isFamily("windows")) {
           // Determine if we're running under XP/2000/NT/2003 or 98/95
            if (Os.isFamily("win9x")) {
                // Windows 98/95
                String[] cmd = {"command.com", "/c", "set" };
                return cmd;
            } else {
                // Windows XP/2000/NT/2003
                String[] cmd = {"cmd", "/c", "set" };
                return cmd;
            }
**************************************************************************
I didn't check the source code of other Ant versions. If they have the same 
snippet causing ntvdm.exe exception you may want to use my fix for them too. 

Regards,
Irene.

Irene Rusman.
Sr. Software Engineer,
BEA Systems.
irusman@bea.com
office: 408.570.8529