Re: Dying laptop?
CPU fan or hard drive. If it's the fan most likely the inside is full of dust and needs to be blown out. Canned air only. If it's never been cleaned it might be prudent to take it to a shop and let them open it up and give it a through cleaning.
If you suspect the hard drive then run a hard drive diag by using the drive tools from the hard drive maker's website. If it's showing it's failing BACKUP every thing important to you and replace the drive.