[dweez11]

I've been running Windows XP on my 2006 Macbook for almost a year now. It recently has started making the Windows startup sound for no reason. This is after I turn off sound before shutdown and have speakers plugged in (turned off). The internal speakers have the sound.
I've gone into Control Panel to turn off all sounds that Windows should make and I think I deleted the right sound file for that sound. However, it keeps happening.
My friend says his computer does it sometimes too and there isn't anything I can do since it's Firmware issues or something.

Is there a way I can fix this?