How to fix Error 1321 on Windows 11

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Troubleshooting Guide: Error 1321 on Windows 11

Why This Error Happens

Error 1321 occurs when the Windows Installer service attempts to modify a file or registry key but the current user account lacks sufficient NTFS permissions to do so, typically because the account is not part of the required security group. This is commonly triggered when installer packages check permissions against the “Users” or “Administrators” group but the executing profile has restricted or corrupted access tokens. It can also happen if the user profile itself is corrupted or if permissions on the Windows Installer cache folder have been altered by a third-party security tool.

Step-by-Step Resolution Guide

Step 1: Verify and Modify Local Group Membership

  • Press Windows + R, type lusrmgr.msc, and hit Enter to open Local Users and Groups.
  • Navigate to the Groups folder and double-click Administrators.
  • Ensure the affected user account is listed; if not, click Add, type the username, and click Check Names to validate.
  • Click Apply and restart the installation process.

Step 2: Reset Permissions on the Installer Cache Folder

  • Open File Explorer and navigate to C:\Windows\Installer.
  • Right-click the folder, select Properties, and go to the Security tab.
  • Click Advanced, then select Change permissions.
  • Check the box for “Replace all child object permissions with inheritable permissions from this object” and click OK.
  • Confirm the security prompt to apply the changes recursively.

Step 3: Run the Installation Using an Elevated Administrator Account

  • Right-click the installer file (.msi or .exe) and select Run as administrator.
  • If the error persists, log out and log in using a Local Administrator account instead of a Standard User account.
  • Temporarily disable third-party antivirus software, as some security suites block registry modifications during installation, mimicking a permissions error.

Step 4: Create a New Local User Profile (If Corruption is Suspected)

  • Go to Settings > Accounts > Other users.
  • Click Add account and create a new local administrator profile.
  • Log into the new profile and attempt the installation again to rule out a corrupted user profile as the root cause.

Alternative or Verification Steps

  • Verification: Open the Event Viewer (eventvwr.msc), navigate to Windows Logs > Application, and confirm that no new Error 1321 or MsiInstaller warnings appear after the setup completes successfully.
  • Alternative Fix: If the error continues, download the official Microsoft Program Install and Uninstall Troubleshooter from support.microsoft.com, as it automatically resets registry permissions and installer cache corruption that manual steps might miss.