Initialization file used with Microsoft Windows 3.x, Windows 95, and Windows 98 to initialize system settings for the computer, such as the fonts, keyboard, language, and other settings. The system.ini file is located in the C:\windows directory and its backup is the system.--- file.
Computers running Windows NT 4.0, 2000, XP, or later operating systems no longer have a system.ini. Instead of storing these settings in the system.ini recent version of Windows stores settings in the system Registry. For backwards compatibility, Windows 2000 and Windows XP may have a very basic or blank system.ini file.