MSConfig

MSConfig, officially called System Configuration or System Configuration Utility, is a utility used to troubleshoot the Microsoft Windows startup process by allowing the user to temporarily disable drivers, services and other applications that launch at startup, as well as change other aspects of system configuration.

History
The utility was introduced with Windows 98, where it replaced the DOS-based "Microsoft Diagnostics". It allowed the user to modify the configuration files of both MS-DOS and Windows, selectively disable the processing of some files at startup, as well as toggle certain troubleshooting settings. For Windows Me, the tool was updated, mostly due to the removal of most access to real mode MS-DOS.

It was ported to the NT-based series with Windows 2000, where it allowed to modify the boot manager configuration, as well as to selectively disable services. The Tools page was also introduced, which serves as a hub to other included system utilities. As it replaced "Windows NT Diagnostics" from earlier Windows NT versions, launching it in Windows 2000 will open MSConfig instead, as the executable file turned into a stub for MSConfig. In Windows Vista, the ability to modify the legacy  and   configuration files. Windows 8 saw the last major update to the tool, as the Startup tab was deprecated in favor of managing applications that run on startup from the redesigned Task Manager.