This started on saturday, after I installed a new case fan, though I don't think this has anything to do withe case fan. Whenever I restart my computer, after the initial first beep the PC case speaker makes, it then makes an annoying high pitched note that does not stop until I manually restart the computer and go into safe mode a couple of times. Honestly, I'm about ready to rip it out of the computer smash it into many little pieces, unless someone can tell me what is wrong. Until then, I think I'll just disconnect the speaker for now. That won't do any harm. **EDIT** Nevermind, problem solved. When I had the case open to install the case fan and new ethernet card, I took out the CPU to do some cleaning. I noticed the computer was running a bit slower since Saturday, because...wait for it... I forgot to plug the power cable for the CPU fan back in. Guess the noise was some kind of warning sound.