There are several possible reasons for the laptop’s fan making loud noises even when idle. To investigate further, try following these steps:

1. Check the internal temperature of the laptop by downloading a temperature monitor program.
2. Check for dust build up inside the laptop and clean out the vents and fan.
3. Check the fan vent openings for obstructions.
4. Check that the fan is spinning freely and not caught on physical objects.
5. Check for the latest updates for the laptop's BIOS and other drivers.
6. Check to see if a different power adapter is available that can provide more power to the laptop if necessary.
7. Check for the latest updates for the laptop's operating system.