INI Files are a series of initialization files used in Microsoft Windows operating systems (Windows 3.1) that store configuration information about hardware, devices, and services on the computer. Some applications and software also use this kind of file to store configuration parameters.

These text files, which have the extension .ini, include:
- WIN.INI, which stores information about the desktop environment, fonts, and printers, as well as other settings
- SYSTEM.INI, which stores boot settings and information specific to running in Standard and 386 Enhanced modes
- CONTROL.INI, which maintains the Windows color schemes
- PROGMAN.INI, which stores information about program groups
- WINFILE.INI, which stores status information for File Manager
In addition, individual applications often create their own INI files during installation to store application-specific settings.
NOTE
Instead of using INI files, Windows 95, Windows 98, Windows NT, and Windows 2000 store all configuration settings in the registry. Most of these files are also included in these operating systems to provide backward compatibility for running 16-bit Windows programs because such programs were designed to save their settings in INI files and cannot access the registry.

However, files such as the desktop.ini file still exist in many versions of Windows today.