How to fix Error 162 on Windows 11

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Windows 11 Troubleshooting Guide: Error 162 – “A Signal Is Already Pending”

Why This Error Happens

Error 162 occurs when a process attempts to raise a signal or asynchronous procedure call (APC) while a previous signal targeting the same thread has not yet been processed or cleared. This is typically caused by overlapping I/O operations, a thread synchronization conflict, or a driver/application that improperly manages event handles. It is frequently seen with backup software, virtual disk drivers, or third-party services that use asynchronous I/O without properly waiting for signal completion before issuing a new one.

Step-by-Step Resolution Guide

  1. Identify the Source Application
    Open Event Viewer (eventvwr.msc) → Windows Logs → Application and System. Look for the exact process name tied to Error 162 in the event details. This is usually a backup agent, disk cloning tool, or antivirus/EDR service.

  2. Update or Reinstall the Offending Driver/Service
    Go to Settings → Windows Update → Advanced options → Optional updates → Driver updates, and install any pending updates for storage or filter drivers (especially disk, volume shadow copy, or virtual disk drivers). If the issue points to a third-party app, uninstall and reinstall the latest version from the vendor.

  3. Check for Pending I/O Conflicts via Task Manager
    Open Task Manager (Ctrl+Shift+Esc) → Details tab, and end any duplicate or hung instances of the reported process. Multiple instances of the same backup/sync tool running simultaneously is a common trigger.

  4. Repair System Files
    Run the following commands in an elevated Command Prompt or Windows Terminal (Admin) to fix corrupted system components that manage signal/APC handling:

   sfc /scannow
   DISM /Online /Cleanup-Image /RestoreHealth

Restart the machine after completion.

  1. Disable Conflicting Background Services Temporarily
    Open services.msc, locate the service associated with the failing app (e.g., Volume Shadow Copy, backup agent service), right-click → Restart. If the error persists, temporarily set it to Manual startup and reboot to confirm whether it resolves the conflict.

Alternative or Verification Steps

  • Verify the Fix: Re-run the operation that triggered Error 162 (e.g., backup job, disk sync) and monitor Event Viewer for recurrence. No new Error 162 entries within a full operation cycle confirms resolution.
  • Alternative Fix: If the error persists, boot into Safe Mode with Networking, run the affected application in isolation, and check if the error still occurs — this helps confirm whether a third-party driver conflict (not Windows itself) is the root cause.