No. It just means DISM didn’t understand your command. Your system files are safe.

Sometimes the DISM command parser itself becomes corrupted. Run SFC first:

If you are copying commands from a website, paste them into Notepad first and look for auto‑formatted slashes.

The good news is that Error 87 is rarely a sign of hardware failure; instead, it is typically a permission Common Causes of Error 87 Incorrect Syntax:

Ensure spaces before every / and include the dash in /Cleanup-Image . Right-click CMD and select "Run as administrator". Outdated Windows Install all pending updates in Settings. Service Stopped Enable "Windows Modules Installer" in Services. Incorrect Environment Use /Image instead of /Online if in Recovery Mode.