This is my version of Windows 2000 Beta 3. V1.3.2. Rest is simple. When you pressed the flag, wait 65 seconds and then start to play. When you pressed shutdown from the start menu, wait 60 seconds and then hear the shutdown sound.
Thanks to zombieliukang for the original project Windows 2000 Beta 3 (zombieliukang's version V1.3.2).
