Definition: Win Safe Mode
Windows has a startup mode for troubleshooting that allows the system to boot up when it otherwise may not, often due to conflicts from newly installed hardware. Only the mouse, keyboard and standard VGA display drivers are loaded, and all configuration files are bypassed, including the Registry and any earlier CONFIG.SYS, AUTOEXEC.BAT and SYSTEM.INI files that may be present. In Safe mode, configuration data can be manually edited, but technical knowledge is required.
Windows automatically boots up in this mode if it detects that the previous session was not shut down properly. To purposely start up in Safe Mode in Windows XP and 7, press F8 after turning the computer on and before Windows starts.
In Windows 8.1 and 10, hold Shift down while clicking Restart.