I tried it on both my system (Windows XP) and the test one and it ran fine on mine: "C:\WINDOWS\system32\cmd.exe" is a valid path!

I just got an @ERROR of 255 and no output when trying the same code on the test system.

I guess that's why I'm asking about the internals of the shell command, but maybe this is related to CMD.EXE? I looked through autoexec.nt and config.nt on both my system and the test one and found no differences. These two files may only affect things executing under COMMAND.COM, though.