1. The CPU or other part is overheating.
2. Some malware, trojan, virus is in the machine.
If you don't repair your own gear, arrange to take or send it in.
I have a Toshiba mod.# p205-56237 operating on windows vista that is making a siren noise through the speakers. It only stops when I mute the speakers. This noise will not stop and goes up and down in volume. Please help.