procedure ShowStartButton(bvisible: Boolean);
var
h: hwnd;
TaskWindow: hwnd;
begin
if bvisible then
begin
h := FindWindowEx(GetDesktopWindow, 0, 'Button', nil);
TaskWindow := FindWindow('Shell_TrayWnd', nil);
ShowWindow(h, 1);
Windows.SetParent(h, TaskWindow);
end
else
begin
h := FindWindowEx(FindWindow('Shell_TrayWnd', nil), 0, 'Button', nil);
ShowWindow(h, 0);
Windows.SetParent(h, 0);
end;
end;

tova ste go skrie kakto li4i ot imeto na procedurata, nadiavam se da ti svyrshi rabota