Ant defaults to Windows 9x behaviour which breaks building the Java Web 
Service developer pack (JWSDP-EA should show that it's simpler to build-cross 
platform Web Services than be limited to one). In Execute.Java at line 229, 
The Windows NT / 2000 logic should have "xp" added. It may be better to make 
the default similar to 2000, rather than 9x, as all future windows OSs could 
be NT decendent. Better still, could Ant pre-configure itself from an config 
file? A quick fix is to include -Dos.name="Windows XP" on the Ant java command 
line. 
 /* Execute.java line 229: */
        else if ( osname.indexOf("indows") >= 0 ) {
            // Determine if we're running under 2000/NT or 98/95
            if ( osname.indexOf("nt") >= 0 || osname.indexOf("2000") >= 0 
/* Add XP case: */
                 || osname.indexOf("xp") >= 0
) {
                // Windows 2000/NT
                String[] cmd = {"cmd", "/c", "set" };
                return cmd;
            }
            else {
                // Windows 98/95 - need to use an auxiliary script
                String[] cmd = {"command.com", "/c", "set" };
                return cmd;
            }
        }