Try updating the power management drivers.
First make sure that the laptop is using the most current version of the power management software. If not, update the drivers. Follow these steps:
1. Go to "Control Panel" and then click "Device Manager".
2. Double click and open "System Devices".
3. Right-click "Microsoft ACPI-Compliant System".
4. Now choose "Update Driver Software".
5. Carefully read all the instructions onscreen.
You may wish to also repeat these instructions, but right-click "Microsoft ACPI-Compliant Embedded Controller" in Step 3. (if located on your system)
If this doesn't work, you may need to go to the laptop manufacturer’s website and search their support section and locate any new power management drivers...