Troubleshooting Guide: Error 440 – Invalid Parameter During File Snapshot Operation

Why This Error Happens

Error 440 typically occurs when the Volume Shadow Copy Service (VSS) or a related snapshot utility receives a malformed or unsupported parameter while attempting to create or access a file snapshot. This is often caused by corrupted VSS writer components, an outdated or mismatched storage driver, or insufficient permissions on the target volume. In some cases, third-party backup or disk management software passes incompatible flags to the Windows snapshot API, triggering this invalid parameter response.

Step-by-Step Resolution Guide

Verify VSS Service Status
Press Win + R, type services.msc, and press Enter. Locate Volume Shadow Copy, right-click it, and select Restart. Ensure the Startup type is set to Manual.
Check VSS Writer Health
Open Command Prompt as Administrator and run:

   vssadmin list writers

Look for any writer showing a state other than “Stable” or with an error. If a writer is failing, restart the associated service (e.g., restart the “COM+ Event System” for VSS-related writer issues).

Re-register VSS DLLs
In an elevated Command Prompt, run the following commands sequentially to re-register core VSS components:

   cd /d %windir%\system32
   net stop vss
   regsvr32 /s ole32.dll
   regsvr32 /s oleaut32.dll
   regsvr32 /s vss_ps.dll
   vssvc /register
   net start vss

Run System File Checker and DISM
Corrupted system files can trigger invalid parameter errors during snapshot creation. Run:

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

Restart your computer once both scans complete.

Confirm Disk and Permissions
Right-click the target drive in File Explorer → Properties → Security tab. Ensure the SYSTEM account has Full Control. Also run chkdsk C: /f (replace C: with your target drive) from an elevated Command Prompt to rule out underlying disk corruption.

Alternative or Verification Steps

After applying the steps above, attempt the snapshot operation again and re-run vssadmin list writers to confirm all writers report a “Stable” state with no errors.
If the issue persists, create a new System Restore point manually via Control Panel > System > System Protection; if this also fails with Error 440, consider performing a Windows 11 in-place upgrade repair to reset corrupted system components without losing data.