Sets MenuShowDelay = "20" (milliseconds) under Control Panel\Desktop; the Windows default is 400. This is the delay before cascading/submenus appear — dropping it from 400 ms to 20 ms makes the classic right-click 'Show more options' menu, Control Panel menus and other Win32 flyouts feel near-instant while still avoiding accidental pop-ups (0 is not recommended as menus become hard to skim). Note: modern WinUI surfaces like the Win11 Start menu ignore this value. Sign out/in to apply. Reversible; revert restores the prior value (default "400").
MaxTweaks applies this tweak with one click and snapshots your original setting first, so you can revert it cleanly at any time. A System Restore point is offered before batch changes, and every tweak links to its official source.
Get MaxTweaksOfficial documentation: https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-systemparametersinfow