Troubleshooting why your laptop’s fan suddenly starts running loudly:

1. Clean out any dust or debris from the intake and exhaust vents.
2. Make sure the laptop’s temperature is not too hot.
3. Reinstall the system fans or reset settings.
4. Monitor which applications are running to identify a performance issue.
5. Check for viruses or malware.
6. Consider a laptop cleaning.
7. Reinstall the laptop’s operating system.