Try this in TCC v14.02.44: Type OPTION and press Enter. Select the "Advanced" tab. Make any change, or none at all; click on OK. Then try to execute any command followed by an argument.
This is behavior appeared quite recently. I'm pretty sure that build 42 didn't do it. Nor does the current TCC/LE.
C:\>ver /r TCC 14.02.44 Windows XP [Version 5.1.2600] TCC Build 44 Windows XP Build 2600 Service Pack 3 Registered to Charles Dye - 5 System License C:\>option C:\>ver /r TCC: Unknown command "ver" C:\>set path TCC: Unknown command "set" C:\>echo foo TCC: Unknown command "echo" C:\>dir * TCC: Unknown command "dir" C:\>