Cpu makes weird noise on boot

Hello,
My cpu makes weird noise on boot up but quiets down within a few minutes, only started doing this recently. After the blue screen came up the other day. It said that windows was shutting down to avoid damage to computer. Also have had a issue with an error saying not authorized for this action or something like that. There is no one else who uses the pc, home office use only.
The noise is like a far away thunder storm growling in the back ground.