Heat monitoring programs may not work properly so at least you could check up cpu's temp in bios.
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Try to unistall the Gpu you have now in order to install a new one,or else make it with the [onboard gpu reguires enable in bios] .
update pc's drivers.
Try reseting your bios.
If nothing of the above works , try another power supply.
also you could try installing a new bios battery.
Did you make any pc hardware changes lately ? like new gpu install?if yes , maybe the power can not put up with the changes.
If you don't know how to do some of the above, there are many videos in youtube.
If you really don't know how to do some of the above do not risk it without even watching a video tutorial , because you may then cause pc problems.
Good Luck :)
Hope i helped.