Understanding the root cause helps prevent the error from recurring. The most common triggers include:
If you are trying to use the /RestoreHealth switch on an older version of Windows (like Windows 7), you will get Error 87 because that specific parameter didn't exist yet.
If you’re still stuck, run:
The DISM command must have a space before every forward slash. Incorrect: dism/online/cleanup-image/restorehealth dism /online /cleanup-image /restorehealth 2. Run as Administrator Always ensure you are using an Elevated Command Prompt in the Windows search bar. Right-click "Command Prompt" and select Run as Administrator Type the command again. 3. Run the SFC Tool First Sometimes, the System File Checker (SFC) dism error 87 fixed
The absolute most common cause of Error 87 is formatting. Windows commands are highly sensitive to spacing. If you string the parameters together without spaces, the system reads it as a single invalid parameter. DISM.exe /Online /Cleanup-Image /RestoreHealth Correct: DISM.exe /Online /Cleanup-Image /RestoreHealth
Execute the following command (replace E with your actual mounted drive letter): DISM /Online /Cleanup-Image /RestoreHealth /Source:WIM:E:\sources\install.wim:1 /LimitAccess Conclusion
If you still get Error 87, your local Windows image component store might be completely broken. In this scenario, you must tell DISM to fetch repair files from an external, healthy source—like a Windows installation USB or ISO file—rather than using Windows Update. How to use a clean Windows Source: Understanding the root cause helps prevent the error
Running the Command Prompt as a standard user instead of an Administrator.
Sometimes, the Command Prompt environment introduces odd parsing errors. PowerShell handles arguments differently and may bypass Error 87 entirely.
To resolve DISM error 87, it's essential to understand its underlying causes. Some of the common causes include: To resolve DISM error 87
While seeing "The parameter is incorrect" can be alarming, DISM Error 87 is usually a simple matter of formatting permissions
DISM /Online /Cleanup-Image /RestoreHealth