How to fix Error 1155 on Windows 11

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Windows 11 Error 1155: No Application Associated With File

Why This Error Happens

Error 1155 occurs when Windows cannot find a program registered to open a specific file type, typically because the file extension’s registry association is missing, corrupted, or was removed during a software uninstallation. This commonly happens after uninstalling an application that was the default handler for that file type, or when file association entries in the Windows Registry (under HKEY_CLASSES_ROOT) become damaged. It can also occur when attempting to execute a file type through a command line or script (like .vbs, .bat, or custom extensions) that has no default action defined.

Step-by-Step Resolution Guide

  1. Manually Set a Default App:
  • Right-click the problematic file and select Open with > Choose another app.
  • Select an appropriate application, check Always use this app to open .[extension] files, and click OK.
  1. Reset File Associations via Settings:
  • Go to Settings > Apps > Default apps.
  • Search for the file extension in question, click it, and manually assign a compatible program.
  1. Check and Repair Registry Associations:
  • Press Win + R, type regedit, and press Enter.
  • Navigate to HKEY_CLASSES_ROOT\.[extension] (e.g., .txt, .docx).
  • Verify the key has a valid string value pointing to a ProgID (e.g., txtfile). If missing or broken, create/correct the string value to match a valid program identifier found elsewhere in HKEY_CLASSES_ROOT.
  • Back up the registry before making changes (File > Export).
  1. Use Command Prompt to Reassociate via ftype/assoc:
  • Open Command Prompt as Administrator.
  • Run assoc .[extension] to check current association status.
  • If blank or broken, set it manually: assoc .txt=txtfile followed by ftype txtfile="C:\Path\To\Program.exe" "%1".
  1. Run System File Checker (SFC):
  • Open Command Prompt as Administrator.
  • Run sfc /scannow to repair corrupted system files that may be affecting registry integrity or default handlers.

Alternative or Verification Steps

  • Verify the fix: Double-click the file type again — it should now open with the assigned application without triggering Error 1155.
  • Alternative fix: If registry edits fail, use a third-party tool like NirSoft’s FileTypesMan to safely inspect and repair file type associations without manual registry editing.