Here is a list of things you can do if your laptop’s fan is running constantly on high speeds after a system update:

1. Check for system updates: Make sure that you have all the most recent updates installed in order to ensure optimum running speeds.
2. Check your fans: Make sure your fans are firmly affixed and clean from dust. If they are unduly noisy, you may need to replace them.
3. Check your venting: Make sure that your laptop is able to properly vent both hot air coming out of the laptop and cool air to keep the laptop working properly.
4. Check your power settings: Make sure that your laptop’s power settings are appropriate. If the laptop is set to maximum performance, the computer may be overworking itself and causing the fan to run more than necessary.
5. Check the temperature of your components: If your computer components are being pushed to their upper limits and overheating, this can cause the fans to be in overdrive.