High pitched noise from PC.

[flobadob]

I've noticed recently when I turn on the computer there is a high pitched noise coming from it which lasts for about 5 minutes. Also when I disconnect a USB stick using the remove hardware icon the same thing happens. So far it has always stopped after a little while but it's quite an annoying noise. What is causing this and should I be worried?

[kujawski]

there might be a mouse in there, who

1) doesnt like being woken up
2) doesnt like usb devices being unplugged

[flobadob]

So perhaps if I crammed a slice of cheddar in the back it would be problem solved.

[Ethel]

I had this on my laptop and found the only way to stop it was to switch the audio boost off in the sound settings in the control panel.

[beso]

Some computers have temperature controlled cooling fans. In cold weather they sometimes don't start until the computer warms up.

They also have a fan failure warning alarm which will sound because the fan has stopped. Check your BIOS settings.

Smart fan + fan failure alarm + cold weather = noise.

However the USB part doens't fit this scenario.