⚠️ 2 verified solutions available for Error 1400 — Last updated 2026-03-05
Error 1400 📋

Fix ERROR_INVALID_WINDOW_HANDLE — Windows Error Code 1400

Error 1400 (ERROR_INVALID_WINDOW_HANDLE) is a Windows Security & Privileges error that occurs when invalid window handle.. This guide provides step-by-step solutions to resolve this issue.

🏷️ Code: 1400 📛 ERROR_INVALID_WINDOW_HANDLE 📅 Updated: 2026-03-05 ⏱️ 2 Solutions
⚡ Quick Fix

Run as Administrator: Right-click the application → 'Run as administrator'

👇 See all 2 solutions below
🐞 Auto-Fix Script for Error 1400
⚠️ How to use: Open PowerShell as Administrator, paste the code above, and press Enter.
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📑 Table of Contents
What is Error 1400? Common Causes Step-by-Step Solutions Prevention Tips Related Errors

💡 What is Error 1400?

Windows System Error Code 1400, known as ERROR_INVALID_WINDOW_HANDLE, is a Security & Privileges error that occurs during security, authentication, and user privileges. The error indicates that: Invalid window handle. When this error is encountered, the Windows operating system was unable to complete the requested operation within the security services subsystem. The error code 1400 is returned by the GetLastError() function and provides developers with a specific identifier to diagnose the root cause of the failure. The symbolic name ERROR_INVALID_WINDOW_HANDLE maps directly to this numeric code and is commonly referenced in Microsoft documentation, developer forums, and system logs. Understanding this error and its context within security, authentication, and user privileges is essential for effective troubleshooting.

⚠️ Common Causes

  • System resource conflict: Invalid window handle.
  • User account lacks required permissions
  • Group Policy restricts access
  • Authentication credentials expired
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✅ Step-by-Step Solutions

1 Run as Administrator
  1. Right-click the application → 'Run as administrator'
  2. If Error 1400 (ERROR_INVALID_WINDOW_HANDLE) resolves, it's a permissions issue
  3. For permanent fix, right-click → Properties → Compatibility → check 'Run as administrator'
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2 Check User Account Permissions
  1. Open Computer Management (compmgmt.msc)
  2. Navigate to Local Users and Groups → Users
  3. Verify your account is in the Administrators group
  4. If not, add it and log off/on

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💻 Diagnostic Command

Run this PowerShell command to find related events in your system log:

Get-EventLog -LogName System -Newest 20 | Where-Object {$_.Message -like "*1400*" -or $_.Message -like "*ERROR_INVALID_WINDOW_HANDLE*"} | Format-List

💡 Open PowerShell as Administrator, paste the command above, and press Enter.

🛡️ Prevention Tips

  • Apply least-privilege principle
  • Audit user accounts regularly
  • Keep security policies and AV updated
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Last updated: 2026-03-05
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Based on Official Microsoft Documentation
Solutions Tested on Windows 10 & 11
Error codes sourced from Microsoft Win32 SDK. Updated 2026-03-05.
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