Sometimes the DISM command parser itself becomes corrupted. Run SFC first:
sfc /scannow
Then restart and try DISM again.
In 90% of cases, Error 87 is caused by a missing colon after Online. Many old tutorials omit the colon, but modern Windows versions require it strictly.
Incorrect (causes Error 87):
DISM /Online /Cleanup-Image /RestoreHealth
Correct (works perfectly):
DISM /Online: /Cleanup-Image /RestoreHealth
Notice the colon after Online? That tiny punctuation mark is critical. Apply this to any DISM command:
Pro Tip: Always write
Online:with a colon and a space before the next switch.
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
If you are trying to repair your Windows system image using the Deployment Image Servicing and Management (DISM) tool, seeing Error 87 can be frustrating. The error message usually reads:
“Error: 87, The parameter is incorrect.”
This is one of the most common DISM errors, but fortunately, it is also one of the easiest to resolve. It rarely indicates a serious system failure; instead, it is almost always caused by a typing mistake or a misunderstood command syntax.
In this guide, we will explain why this error happens and provide the exact steps to fix it. dism error 87 fixed
No. It just means DISM didn’t understand your command. Your system files are safe.
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. Sometimes the DISM command parser itself becomes corrupted