Ear piercing sounds emits when I turn on computer

[Daisy3232]

Ear piercing sounds emit when desktop is turned on.

[WAWood]

@Daisy3232 

If this is a screeching sound, with a vibration to it, that is likely to be a damaged fan with  worn out bearing.  It will be loudest when the PC starts because the fan spins up initially and then slows down.  If this is what is happening, it is most likely to be fan damage -- and that would need to be removed and replaced.

Another possibility is audio feedback -- which is what can happen if the microphone is enabled and the speaker volume is turned up to the max.  To check this out, look down at the system tray at the bottom right of the screen and look for a speaker icon.  If you right click on that, you should be able to mute the speaker.  If that stops the sound, that is the issue.