If so, move to Fix 2. Fix 2: Update Your Windows 7 DISM Tool (The "KB2966583" Fix) If you receive Error 87 even when using the /Source parameter, your DISM binary is too old to understand the /RestoreHealth argument at all.
Specifically, the /RestoreHealth switch with the /Online flag behaves entirely differently on Windows 7. If you copy-paste a Windows 10 command into a Windows 7 CMD window, you will trigger Error 87 immediately. Fix 1: Use the Correct Syntax for Windows 7 You cannot use /RestoreHealth directly on a live Windows 7 OS using the built-in DISM. Instead, you must target an offline image.
Error 87 is arguably the most frustrating error you will encounter when running the Deployment Imaging and Servicing Management (DISM) tool on Windows 7 .
Let’s break down exactly why this happens on Windows 7 and how to fix it for good. Here is the hard truth most tutorials won't tell you: DISM on Windows 7 is ancient.
