Sometimes, you just need a shell. Especially if you are debugging something on a machine that is locked down and won't let you use the local cmd.exe... doubly so if you have to re-login or reboot to escalate your privileges, in which case the problem you are trying to identify will go away.
What to do? Either have another shell on a disk with you, or download one here. As an added bonus, since these two are replacement shells, they don't play along with Group Policy rules that prevent the native cmd.exe from running. So sad.
Since it is not ethical to distribute the original command.com and cmd.exe, here is a Free replacement for each. (Note: the command.com replacement does not run well outside of FreeDOS, it seems to bog down WinXP. Its just here in case I find a need for it.)
This is the cmd.exe from ReactOS. It is unmolested, other than being run through UPX in order to save some bandwidth:
ReactOS Command Line Interpreter Version 0.2.7-RELEASE 20050820-r17449 Copyright (C) 1994-1998 Tim Norman and others. Copyright (c) 1998-2005 ReactOS Team ReactOS Command Line Interpreter comes with ABSOLUTELY NO WARRANTY; for details type: `ver /w'. This is free software, and you are welcome to redistribute it under certain conditions; type `ver /r' for details. Type `ver /c' for a listing of credits. Send bug reports tocmd.exe from ReactOS. Updates are available at: http://www.reactos.com
This is the command.com from FreeDos (FreeCom):
FreeCom version 0.82 pl ak XMS_Swap [Aug 18 2004 23:00:58]command.com from FreeDOS