Supporting the Keyboard Preference Flag
An application that normally hides some keyboard user interface elements or omits some keyboard mechanisms altogether should present them when the Keyboard Preference flag is set. This flag, which is set by the user in Control Panel, advises an application that the user relies on the keyboard rather than a pointing device, so additional support should be provided where appropriate. An application can test for this flag by calling the SystemParametersInfo function with the SPI_GETKEYBOARDPREF value.