|The CPU *may* be overheating, but there are no temps listed so that would be strictly a guess. It could also be a problem with the video card or the power supply fans or the case could simply be full of dust. Not enough info was provided.|
If you haven't cleaned the inside of the case lately, open it up & blow out the dust with compressed air, especially the heatsinks & cooling fans. Do NOT use a vacuum. And while you have the case open, get the power supply specs off the label...make/model, wattage & amperage specs. Temporarily leave the side panel off the case.
Bootup & immediately enter the BIOS...go to the PC Health menu & monitor the CPU temp. Report back what it is. If the high pitched noise is still there, see if you can pinpoint where it's coming from.