How to Fix DISM Error 87 in Windows?

DISM Error 87 usually appears when Windows cannot understand a DISM command or one of its parameters. You may see “Error: 87” along with a message such as “The cleanup-image option is unknown”, even though the command looks correct.

In many cases, the problem is a syntax or spacing mistake rather than serious Windows corruption. This guide explains what causes the error in Windows, how to fix it, and how to avoid it in the future.

What Causes Error 87 When Running DISM?

Error 87 DISM means DISM (Deployment Image Servicing and Management) could not process the command it received. The exact message depends on the command, but “DISM cleanup image option is unknown” usually means that it did not recognize the /Cleanup-Image parameter correctly.

The most common cause is incorrect command syntax. For example, people use the command without spaces:

DISM.exe/online/cleanup-image/restorehealth

The standard command for repairing the currently running Windows installation includes spaces. The spaces between the command and each parameter matter. Other possible causes include

• A typing error in the DISM command.
• An option that is not supported in the current servicing context.
• An incompatible or outdated DISM version being used with a newer Windows image.
• An incorrect /Source path when a repair source is specified.

The commands and options available to DISM can also vary depending on whether you are servicing the running Windows installation or an offline image.

So, if you see DISM /online /cleanup-image /restorehealth Error 87. It does not necessarily mean Windows is corrupted. In many cases, DISM is rejecting the command before it can perform the requested operation.

How to Fix DISM Error 87 in Windows?

Start with the basic syntax and move to image repair only if the command still fails. Let’s see how to tackle the “The cleanup-image option is unknown” error.

1. Open Command Prompt as Administrator

DISM commands that repair Windows while troubleshooting errors like System Service Exception BSOD and others should be run from an elevated Command Prompt.

• Search for Command Prompt in Windows.
• Right-click it and select Run as administrator.

  

• Select Yes when the User Account Control (UAC) prompt appears.

Microsoft recommends using an elevated Command Prompt for DISM and SFC repairs.

2. Run the Correct DISM RestoreHealth Command

This is one of the most basic mistakes. You just need to enter the following command exactly as shown:

DISM.exe /Online /Cleanup-Image /RestoreHealth

Make sure there is a space between:

• DISM.exe and /Online
• /Online and /Cleanup-Image
• /Cleanup-Image and /RestoreHealth

Here, /Online tells DISM to service the currently running Windows installation, while /Cleanup-Image enables Windows image servicing, and /RestoreHealth checks for component-store corruption and attempts to repair it.

Press Enter and allow the process to finish. Do not close Command Prompt while DISM is running.

3. Check the Windows Image for Corruption

If /RestoreHealth still fails, check the Windows image before trying another repair. 

• Start with: DISM.exe /Online /Cleanup-Image /CheckHealth

  

• If necessary, run the deeper scan: DISM.exe /Online /Cleanup-Image /ScanHealth.

  

  /CheckHealth checks whether the image has already been flagged for corruption, while /ScanHealth performs a more detailed scan of the Windows component store.
  

• If the scan finds a problem, run: DISM.exe /Online /Cleanup-Image /RestoreHealth.

  

4. Run System File Checker

After DISM completes successfully, run System File Checker: 

sfc /scannow

Microsoft recommends running DISM before SFC because DISM can repair the Windows component store that SFC relies on when replacing damaged system files. Wait until the scan reaches 100% before closing Command Prompt.

5. Use a Repair Source If RestoreHealth Cannot Repair Windows

If /RestoreHealth cannot obtain the required files through Windows Update, you can provide a known-good Windows source with /Source.

The general command is:

DISM.exe /Online /Cleanup-Image /RestoreHealth /Source:C:\RepairSource\Windows /LimitAccess

Replace “C:\RepairSource\Windows” with the actual location of the appropriate Windows repair files.

/LimitAccess prevents DISM from contacting Windows Update, while /Source tells it where to find the repair files.

Note that this is an advanced option. Do not use an arbitrary Windows folder as the source. The source must contain suitable files for the Windows installation you are trying to repair.

How to Prevent Error 87 DISM Cleanup-image Option is Unknown?

Most DISM Cleanup Image Option is Unknown Windows 11/10 errors can be avoided by treating commands as exact syntax rather than something you can type randomly.

To avoid such errors, I would advise you to keep these points in mind:

• Use the correct spacing, such as DISM.exe /Online /Cleanup-Image /RestoreHealth.
• Run Command Prompt as administrator when performing system repairs.
  
• Use documented DISM parameters instead of combining switches from unrelated commands.
  
• Do not mix online and offline image syntax. /Online targets the currently running Windows installation, while /Image:<path> is used for an offline Windows image.
  
• Be careful with /Source and make sure the repair files match the Windows installation you are servicing.
  
• Keep Windows and its servicing tools up to date when possible, especially when working with newer Windows images.
  
• Save frequently used DISM commands somewhere reliable instead of recreating them from memory. This can significantly reduce the chances of making syntax mistakes.

A missing space, altered parameter, or incorrect servicing option can turn an otherwise valid DISM command into Error 87. 

Final Thoughts

DISM Error 87 looks like a serious Windows repair failure, but it often starts with something much simpler. It happens when DISM cannot understand the command it received.

If you see the clean-up image option is unknown, check the command syntax first. If the command still fails, use /CheckHealth or /ScanHealth to investigate the Windows image. If DISM cannot obtain the required repair files, provide an appropriate /Source. Once DISM completes successfully, run sfc /scannow to check and repair protected Windows system files.