SHELL--Notes Default setting The default command interpreter for MS-DOS is COMMAND.COM. If you do not use a SHELL command in your CONFIG.SYS file, MS-DOS searches for COMMAND.COM in the root directory of your startup drive. You need to use the SHELL command if you want to specify a COMMAND.COM file that is not in the root directory or if you do not want to use the default environment size for COMMAND.COM. For information about COMMAND.COM switches, see the command. Using switches with a command interpreter The SHELL command itself does not accept any switches, but if the command interpreter does, you can include them on the SHELL command line.