Resolving DISM Error 87: A Guide to Restoring System Integrity
Sometimes the DISM command parser itself becomes corrupted. Run SFC first:
How to Fix DISM Error 87
DISM is picky about slashes and colons. Remember:
If you have verified the syntax and the error persists, you may need to check your source media paths or restart your Windows Update services.
Sometimes, if the underlying Windows Update service is disabled or hung, DISM (which relies on it for source files) cannot complete the request. How to Fix DISM Error 87 1. Check Your Spacing (Most Likely Fix)