Code:

procedure hideStartbutton(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) = 'TRAYNOTIFYWND' then

           begin

             if Visi then

               ShowWindow(Child, 1)

             else

               ShowWindow(Child, 0);

           end;

       end;

     Child := GetWindow(Child, GW_HWNDNEXT);

   end;

end;