Keyboard Layout

The key HKCU\Keyboard Layout defines the keyboard layouts that you configure using the Regional And Language Options dialog box. In essence, a keyboard layout maps the physical keys on your keyboard to the characters they generate. Keyboard layouts enable you to write German text using a U.S. English keyboard, for example. This key sometimes contains a single REG_DWORD value, Attributes, which determines which key to use for Caps Lock. If this value is 0, Windows XP uses the Caps Lock key. If this value is 0x10000, the operating system uses the Shift key. You sometimes see three subkeys in HKCU\Keyboard Layout:

• Preload. This subkey contains the ID of each keyboard layout the user chooses through the Regional And Language Options dialog box. Windows XP uses this data to restore the keyboard layout when the user logs back on. The first value is 1, the second is 2, and so on. The value 1 is the default keyboard layout.

• Substitutes. This subkey stores the IDs of alternate keyboard layouts. Windows XP checks this subkey when loading a keyboard layout, and if it finds a substitute, it uses that instead of the default layout. This key is usually empty until the user chooses substitute keyboard layouts.

• Toggle. This subkey specifies the key sequences that toggle between input locales. It contains the REG_SZ value Hotkey, which can have one of four values. The value 1 specifies that Left Alt+Shift switches locales. The value 2 specifies Ctrl+Shift, 3 disables the key sequence altogether, and 4 specifies the accent grave key when the default locale is Thai.