Fix ACPI event registration error 0XC0140020 in Windows

Quick answer

Run sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth in an admin command prompt, then update your chipset drivers and BIOS. That resolves 90% of these registration failures.

What this error means

The 0XC0140020 error shows up when Windows can't register an Advanced Configuration and Power Interface (ACPI) event. ACPI is the layer between your OS and motherboard firmware. It handles sleep states, battery info, thermal zones, and device plug-and-play. When registration fails, you'll see this in the System Event Log (Event ID 4 or 12) or as a pop-up after driver installs. It's common after a Windows update, driver rollback, or hardware change — especially on older laptops running Windows 10 22H2 or Windows 11 23H2.

Fix steps

1. Open an admin command prompt. Click Start, type cmd, right-click Command Prompt, select Run as administrator. Accept the UAC prompt.
2. Run System File Checker. Type sfc /scannow and press Enter. This checks for corrupted system files. Wait for the scan to finish — it can take 10-20 minutes. After it says "Windows Resource Protection found corrupt files," don't reboot yet.
3. Run DISM to repair the system image. Type DISM /Online /Cleanup-Image /RestoreHealth and press Enter. This takes 15-30 minutes. After it completes, reboot your PC.
4. Update chipset drivers. Go to your motherboard or laptop manufacturer's support site (Dell, HP, Lenovo, ASUS, etc.). Download and install the latest chipset driver for your exact model. Don't rely on Windows Update — it's often behind.
5. Update BIOS or UEFI firmware. Same support site — find the latest BIOS version. Read the release notes. If it mentions ACPI or power management fixes, install it. Warning: don't update BIOS on a laptop with less than 30% battery. Follow the manufacturer's instructions exactly. After flashing, reboot.
6. Disable fast startup (temporary). Open Control Panel, go to Power Options, click "Choose what the power buttons do," then "Change settings that are currently unavailable." Uncheck "Turn on fast startup (recommended)." Click Save changes. Reboot.
7. Check the event log. Press Windows + R, type eventvwr.msc, press Enter. Expand Windows Logs, select System. Look for any ACPI-related events (Source: ACPI, Event ID 4, 5, or 12). If you see repeated "ACPI BIOS" errors, that's a motherboard firmware bug.

Alternative fixes if the main steps don't work

• Run a hardware diagnostic. Most manufacturers include a boot-time diagnostic (press F12 at startup for Dell, F2 for HP). Run the extended test on the memory and motherboard. Faulty RAM can corrupt ACPI tables.
• Reset BIOS to defaults. Enter BIOS setup (usually F2 or Delete at boot), load optimized defaults, save and exit. This clears any wonky ACPI settings.
• Reinstall the ACPI driver manually. Open Device Manager (Windows + X, select Device Manager). Expand System devices. Look for "Microsoft ACPI-Compliant System." Right-click it, select Uninstall device. Check "Delete the driver software for this device" if available. Reboot — Windows will reinstall the driver automatically.
• Perform a clean boot. Press Windows + R, type msconfig, press Enter. Go to Services tab, check "Hide all Microsoft services," click Disable all. Go to Startup tab, open Task Manager, disable all startup items. Reboot. If the error stops, a third-party service or driver is the culprit. Re-enable things one by one to find it.
• Use Driver Verifier (advanced). Open admin command prompt, type verifier, press Enter. Choose "Create custom settings," next, check all boxes except "DDI compliance checking." Next, select "Select driver names from a list." Sort by Provider, and uncheck all Microsoft drivers. Select third-party drivers only. Apply and reboot. Verifier will crash with a bugcheck if a driver is misbehaving. Only do this if you're comfortable with potential boot loops. Boot into Safe Mode to turn off Verifier: in admin command prompt, type verifier /reset.

Prevention tip

Always check the manufacturer's website for driver and BIOS updates before installing major Windows updates. On Dell and Lenovo systems, the automatic update tools (Dell Command Update, Lenovo Vantage) handle this well. On custom-built PCs, set a calendar reminder to check for chipset updates from Intel or AMD every 90 days. Also, avoid using third-party driver updaters — they push generic ACPI drivers that break registration. Stick with the OEM version.