procedure Startbutton(visi:boolean);
Var Tray, Child : hWnd;
C : Array[0..127] of Char;
S : String;
Begin
Tray := FindWindow('Shell_TrayWnd', NIL);
Child := GetWindow(Tray, GW_CHILD);
While Child <> 0 do Begin
If GetClassName(Child, C, SizeOf(C)) > 0 Then Begin
S := StrPAS(C);
If UpperCase(S) = 'BUTTON' then begin
If Visi then ShowWindow(Child, 1)
else ShowWindow(Child, 0);
end;
End;
Child := GetWindow(Child, GW_HWNDNEXT);
End;
End;

procedure TForm1.Button1Click(Sender: TObject);
begin
startButton(False);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
startButton(True);
end;