https://learn.microsoft.com/en-us/windows/win32/winmsg/wm-settingchange?redirectedfrom=MSDN
WM_SETTINGCHANGE message (Winuser.h) - Win32 apps | Microsoft Learn
A message that is sent to all top-level windows when the SystemParametersInfo function changes a system-wide setting or when policy settings have changed.
wmmessagehappsmicrosoft