✅ There is no space after slashes ( / ), and RestoreHealth is one word.
Ultimately, fixing DISM Error 87 is an exercise in patience and precision. It teaches the user that maintaining a healthy computer requires more than just knowing which tools to use; it requires speaking the language of the machine fluently. By correcting a simple space or elevating their user status, a person can move past the error and restore their system to its peak performance.
Repair via in-place upgrade (if image servicing keeps failing):
DISM (Deployment Imaging and Service Management) is a powerful command-line tool used to service and repair Windows images, including the Recovery environment and Windows Setup. Error 87 is the tool’s way of saying, "I don’t recognize the command or option you just typed." dism error 87 fixed
dism /online /cleanup-image /restorehealth Note the spaces between dism , /online , /cleanup-image , and /restorehealth .
DISM /Online /Cleanup-Image /CheckHealth
To help me tailor any further advice, could you share a bit more context? ✅ There is no space after slashes (
Running the Command Prompt as a standard user instead of an Administrator.
DISM /Online /Cleanup-Image /RestoreHealth /Source:E:\sources
Before diving into the fixes, it helps to understand why this happens. The most common culprits include: Missing a space before a forward slash ( / ). By correcting a simple space or elevating their
DISM /Online /Cleanup-Image /RestoreHealth /Source = E:\sources (spaces around =)
: DISM requires elevated privileges to execute. Type cmd in the Windows Search bar. Right-click Command Prompt and select Run as administrator . Confirm the User Account Control (UAC) prompt.
If you are using the RestoreHealth command, use this exact syntax: powershell DISM /Online /Cleanup-Image /RestoreHealth Use code with caution. If you are trying to check for drivers, use this format: powershell DISM /Online /Get-Drivers Use code with caution. Phase 3: Advanced Solutions