A keyboard-video-mouse (KVM) switch system capable of invoking an on-screen display menu or a hotkey menu with one keystroke rather than a sequence of keystrokes. The KVM switch system includes a KVM processor and at least one menu key. The menu key generates at least one trigger signal based on the keystroke and at least one command is issued to the KVM processor. The KVM processor controls an OSD module and an OSD output control circuit according to the received command to invoke the menu. The OSD module generates the video signals constituting the menu (either OSD menu or hotkey menu). The OSD output control circuit enables the video signals of the menu to be displayed on the monitor of the console.