Autoexec.bat and config.sys can be protected so that their execution is not interrupted. Versions of DOS after Version 6 include the option to interrupt the startup files, or to run through them line by line. The function keys F5 and F8 are used. The function can be disabled by inserting “SWITCHES /N /F” as the first line in config.sys. Nevertheless, the function cannot prevent users from interrupting the startup files by pressing CTRL+BRK or CTRL+C. To protect from this possibility, you need a device driver, provided by most access control programs.