DISM only recognizes forward slashes (/) for options. Backslashes (\) will trigger Error 87 instantly.
Wrong: DISM \Online \Cleanup-Image
Right: DISM /Online: /Cleanup-Image
If you are copying commands from a website, paste them into Notepad first and look for auto‑formatted slashes.
Wrong:
DISM /online /cleanup-image /restorehealth /source D:\sources\install.wim /limitaccess
Corrected:
DISM /Online /Cleanup-Image /RestoreHealth /Source:D:\sources\install.wim:1 /LimitAccess
Older Windows versions (7, 8, early 10) don’t support all modern DISM parameters. Check your version:
DISM /?
Look for supported options:
If you’re on Windows 7: Use the System Update Readiness Tool (CheckSUR) instead of DISM.
DISM /Online /Cleanup-Image /RestoreHealth
If specifying a repair source (e.g., from a Windows ISO mounted as D:):
DISM /Online /Cleanup-Image /RestoreHealth /Source:D:\sources\install.wim:1 /LimitAccess
DISM (Deployment Imaging and Service Management) is a built-in Windows command-line tool used to prepare, modify, and repair system images, including the Windows Recovery Environment (WinRE) and Windows Setup.
Error 87 appears when the DISM command parser receives an argument it doesn’t recognize. This typically happens for one of three reasons:
Let’s be clear: Error 87 does not mean your system is broken. It means your instruction to DISM is broken. dism error 87 fixed
DISM Error 87 – "The option is unknown" is rarely a sign of deep system corruption. In the vast majority of cases, it is simply a syntax error caused by a missing colon, a misplaced space, or the wrong slash type.
By carefully reviewing your command, ensuring /Online: has the colon, and running the tool with administrative privileges, you will resolve this error in under two minutes. For the rare cases where the error persists, repairing your system files with SFC or switching to PowerShell will get the job done.
Now that you know how to fix DISM Error 87, you can return to repairing your Windows image and keeping your PC healthy.
Do you have a specific DISM command that still triggers Error 87? Check the official Microsoft documentation for DISM syntax or leave a comment below for a tailored fix.
How to Fix DISM Error 87: "The Parameter is Incorrect" Encountering DISM Error 87 typically occurs when you are trying to repair a corrupted Windows image or prepare a system for an update. The error message usually states, "The parameter is incorrect" or "The cleanup-image option is unknown."
While this might look like a major system failure, it is most often caused by simple syntax errors—like a missing space—or a lack of administrative privileges. 1. Use the Correct Command Syntax (The Most Common Fix)
The most frequent reason for Error 87 is a formatting mistake. Windows Command Prompt is extremely strict about spacing. The Right Way: Ensure there is a space before every forward slash (/). Correct: DISM /Online /Cleanup-Image /RestoreHealth
Incorrect: DISM/Online /Cleanup-image/RestoreHealth (Missing spaces) Common Typos to Watch For:
Missing dashes: Using /CleanupImage instead of the correct /Cleanup-Image.
Wrong slashes: Using backslashes (\) instead of forward slashes (/). Mispelling DISM: Accidental typos like DSIM. 2. Run Command Prompt as Administrator
DISM requires elevated permissions to access and repair system files. If you run it in a standard user window, it will fail with Error 87. Click the Start menu and type cmd. DISM only recognizes forward slashes ( / ) for options
Right-click on Command Prompt and select Run as administrator. Click Yes on the User Account Control (UAC) prompt.
Rerun your command in the new window (the title bar should say "Administrator"). 3. Enable the Windows Modules Installer Service
If the Windows Modules Installer (TrustedInstaller) service is disabled, DISM cannot execute certain cleanup or repair tasks. Press Win + R, type services.msc, and hit Enter. Locate Windows Modules Installer in the list. Right-click it and select Properties.
Set the Startup type to Automatic and click Start if the service is stopped. Click OK and try running DISM again. 4. Troubleshooting by Windows Version
The available DISM parameters can vary depending on which version of Windows you are running.
Windows 11 & 10: Fully support /RestoreHealth. If you still see Error 87, ensure your Windows is fully updated through Settings > Windows Update.
Windows 7: This version does not natively support the /RestoreHealth parameter in the same way. Users on Windows 7 should use the System File Checker instead by running sfc /scannow.
WinRE (Recovery Environment): If you are running DISM from a recovery screen, the /Online flag might not work because you aren't "inside" the active OS. Use /Image:C:\ (replacing C: with your actual Windows drive letter) instead. 5. Summary Table: Common Fixes Typing Error
Ensure spaces before every / and include the dash in /Cleanup-Image. No Admin Rights 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.
If none of these steps work, your system files might be severely corrupted. In such cases, you may need to perform a Repair Install or a Cloud Reset to restore Windows without losing your personal files. Could you tell me: Which Windows version you're using (10, 11, or 7)? The exact command you typed into the prompt?
If you're running this from within Windows or from a recovery/blue screen? Older Windows versions (7, 8, early 10) don’t
I can provide the specific syntax needed for your exact situation. How to Fix DISM Error 87 in Windows 11, 10 and 7 - SysTools
DISM Error 87 Fixed: A Comprehensive Guide to Resolving the Issue
The Deployment Image Servicing and Management (DISM) tool is a crucial component of Windows operating systems, allowing users to service and manage Windows images. However, users often encounter errors while using DISM, with Error 87 being one of the most common issues. In this article, we will discuss the causes of DISM Error 87 and provide a step-by-step guide on how to fix it.
What is DISM Error 87?
DISM Error 87 is a generic error message that occurs when the DISM tool fails to execute a command. The error message typically reads: "The DISM command failed with error: 87 The parameter is incorrect." This error can occur due to various reasons, including:
Causes of DISM Error 87
The following are some common causes of DISM Error 87:
How to Fix DISM Error 87
Fortunately, fixing DISM Error 87 is relatively straightforward. Here are some methods to resolve the issue:
DISM (Deployment Image Servicing and Management) error 87 (“The parameter is incorrect”) appears when a DISM command is entered with incorrect syntax, unsupported parameters, or when required system components are unavailable. Below is a concise, methodical guide to diagnosing and fixing Error 87 plus practical tips to avoid it.