How to Fix ACPI Wake Alarm Issues on Windows 10/11

Picture this: you’re snuggled into bed, your computer blissfully in sleep mode, and bam—it jolts itself awake like a college student who just remembered an assignment is due. Chances are, the likely culprit behind this restless disruption is the dreaded ACPI Wake Alarm, a sneaky setting hidden deeper than Atlantis itself in your system.
If you've landed here, it's because you've disabled every visible wake timer, waved your digital white flag in frustration, and now you're seeking an expert guide to conquer this vexing beast. Don’t worry, we’ve got you covered! Let’s break this issue down step by step.

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What Is the ACPI Wake Alarm Anyway?​

You’re probably wondering, why does this thing even exist? The ACPI (Advanced Configuration and Power Interface) Wake Alarm is part of your computer’s power management system. Its job is to let specific hardware or scheduled tasks wake the PC from sleep or hibernation. While this can often be incredibly useful—for tasks like automatic backups or system maintenance—things spiral out of control when poorly configured settings, firmware quirks, or rogue applications throw the system into chaos.
The frustration? Even when you disable visible power options like wake timers, the ACPI Wake Alarm can silently override these settings using BIOS/UEFI configurations or system processes buried deep in Task Scheduler.
Let’s dive into how to resolve this stubborn problem.

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Fixing the ACPI Wake Alarm on Windows 11/10​

Here’s a powerful four-course meal of troubleshooting and fixes to tackle this issue head-on. We’ll start simple and work our way to advanced methods.

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1. Adjust Hibernate Settings: Stop the Alarm During Power Transitions​

Your PC might be transitioning from Sleep to Hibernate based on the “Hibernate After” feature, triggering the wake alarm mid-process. Let’s kill the problem at its root.

Steps:​

1. Open the Control Panel, and go to Power Options or type powercfg.cpl into the Run dialog.
2. Select your active power plan, then click Change plan settings.
3. Hit Change advanced power settings.
4. Expand the Sleep section and find Hibernate After.
   • Set this value to 0 (Never) to disable hibernation transitions.
5. After tweaking, launch the following command in Windows Terminal or Command Prompt to analyze:
   

   powercfg /SLEEPSTUDY

   • The command generates a report (usually under C:\WINDOWS\system32\sleepstudy-report.html) that reveals specific wake sources. Look closely to identify the guilty party.

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2. BIOS/UEFI Configuration: The Wake-Source Blackhole​

Sometimes, your PC's firmware is convinced it must keep waking itself up. Adjusting BIOS/UEFI settings is essential.

Steps:​

1. Restart Your PC: During the startup screen, press the BIOS/UEFI entry key (commonly F2, Del, or F12—varies by manufacturer).
2. Find ACPI or RTC Alarm Settings:
   • Navigate to sections like Power Management or Advanced Options.
   • Locate settings referencing terms like “Wake on RTC Alarm” or “ACPI Events” and disable them.
3. Save and exit.

Pro Tip: Between manufacturers' BIOS designs, the actual setting names might differ. Check your PC/motherboard instructions for precise details.

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3. PowerShell & Command Line: Hunting Rogue Timers​

Windows reserves secrets that aren’t always found in its GUI. Thankfully, the command line is your ally.

a) Review All Power Configuration Settings:​

Run this PowerShell command:

powercfg -qh > power_settings.txt

This command outputs all hidden power settings into a handy text file. Search in the file (Ctrl+F) for "ACPI" or "wake timers" to identify possible culprits.

b) Check Active Power Plan:​

Use the following command:

powercfg /getactivescheme

c) Disable Specific Devices from Waking the PC:​

Sometimes a specific device, such as a mouse or NIC, might be responsible for triggering wake sequences:

powercfg -devicedisablewake "<DeviceName>"

Replace <DeviceName> with the exact name listed via:

powercfg -devicequery wake_armed

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4. Disable Wake Timers Explicitly​

Even if you’ve toggled wake timers off through Power Options, here’s a definitive method to ensure wake timers can’t bother you.

Steps:​

1. Open Control Panel > Power Options.
2. Select your power plan, click Change plan settings, then go to Change advanced power settings.
3. Lookup the setting Sleep > Allow wake timers under Advanced Settings:
   • Change this to Disabled for both On Battery and Plugged In scenarios.

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5. Tweak Security and Maintenance​

Windows Maintenance Tasks sneakily use the ACPI alarm to run their routines. Let’s tell those tasks to chill.

Steps:​

1. Open Control Panel, go to Security and Maintenance.
2. Under the Maintenance section, click Change maintenance settings.
3. Uncheck the option to “Allow scheduled maintenance to wake up my computer.”

This prevents scheduled maintenance tasks like Windows Updates or defrag operations from waking your PC.

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6. Investigate Task Scheduler Wake Triggers​

Hidden within the labyrinth of Task Scheduler are tasks that demand the wake alarm’s assistance. Time to rein them in.

Steps:​

1. Open Task Scheduler (taskschd.msc).
2. Go through active tasks under Task Scheduler Library, checking their properties.
3. Under the Conditions tab of each task, uncheck the box for “Wake the computer to run this task.”

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7. Event Viewer Analysis: The Detective's Tool​

Let’s take a forensic approach. The Event Viewer logs every wake event, including the source.

Steps:​

1. Open Event Viewer (eventvwr.msc) and navigate to Windows Logs > System.
2. Use the Find option (Ctrl+F) and search for Wake Source.
3. Look at entries mentioning “Wake Source: ACPI Wake Alarm” to pinpoint exact timings and root causes.

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But Why Does This Keep Happening?​

Even if you’ve systematically disabled wake timers, this issue persists because ACPI operates closer to the hardware layer, often bypassing standard Windows configurations. Some firmware or BIOS/UEFI setups prioritize ACPI functionality, causing the system to ignore OS-level tweaks.

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Final Words​

Disabling the ACPI Wake Alarm is possible with patience and precision. Granted, it might feel like you're taming an unruly teenager at times. However, by systematically targeting Hibernate transitions, BIOS configurations, PowerShell settings, and scheduled tasks, you can regain control over your system's beauty sleep.
Now that you’ve read this guide, what’s been your biggest wake-up horror story? Let us know in the comments below—you might even earn some community support for your woes! Safe (and silent) computing!

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Source: The Windows Club ACPI wake alarm does not disable; How to disable it?