Wikipedia
Sysedit (SYSEDIT.EXE) is a specialized text/ ASCII editor for core Microsoft Windows configuration files (such as PROTOCOL.INI, [[WIN.INI]], [[SYSTEM.INI]], [[CONFIG.SYS]], and [[AUTOEXEC.BAT]]). This executable is installed in the Windows system directory: %windir%\SYSTEM (Windows 3.x and 9x editions) or %windir%\SYSTEM32 (Windows NTx editions). Sysedit was bundled with and automatically installed by every version of Windows from Windows 3.0 up to Windows 98 SE. Support was discontinued with Windows Me. At the time of its initial release, Sysedit was commonly used to demonstrate multiple document interfaces (MDI). It opens all of the aforementioned configuration files at once in separate daughter windows whenever launched. It still uses the System font from older versions of Windows.
Other Microsoft operating systems that include Sysedit are Windows XP, Windows Vista (Service Packs 2 and 3), Windows Server 2008, and Windows 7 (32-bit only).