Отключить ALT_TAB

function ALT_TAB(off:boolean):boolean;
var
OldVal: LongInt;
Dummy:integer;
begin
if off then
SystemParametersInfo (97, Word (True), @OldVal, 0) else
SystemParametersInfo (97, Word (False), @OldVal, 0);
sendMessage(HWND_BROADCAST,WM_WININICHANGE,0,0);
end;