Windows DISM Command Explained

What DISM does

DISM.exe talks to Component-Based Servicing (CBS)—the same subsystem that backs sfc—to service the live component store under WinSxS and optional features. Online repairs fix inconsistencies that prevent Windows Update or SFC from trusting local repair payloads. Offline DISM can patch a mounted Windows image (WIM/VHD) from WinPE or another OS.

Online health and repair

Command pattern	Purpose	Notes
`DISM /Online /Cleanup-Image /ScanHealth`	Longer integrity scan of the store	Read-only check; good first deep signal
`… /CheckHealth`	Fast flag check	Lightweight; may report corruptions flagged earlier
`… /RestoreHealth`	Repair using replacement payloads	Needs Windows Update reachability or an explicit /Source image

Repair sources

When Windows Update is blocked, supply a matching install.wim or install.esd from installation media with /Source:wim:D:\sources\install.wim:1 (index varies) and often /LimitAccess to avoid falling back to Windows Update. Mismatched editions or builds produce HRESULT errors—align SKU, language, and build closely.

Order of operations with SFC

If sfc /scannow cannot repair files, run DISM /RestoreHealth first to heal the store, reboot if pending operations exist, then rerun SFC. DISM logs to %windir%\Logs\DISM\dism.log; CBS still logs broader servicing to %windir%\Logs\CBS\CBS.log.

Frequently Asked Questions

Q.Do I need Administrator to run DISM?

Yes. Open an elevated Command Prompt or PowerShell as Administrator. DISM modifies protected servicing state.

Q.What is the difference between ScanHealth and RestoreHealth?

ScanHealth performs a deeper scan of the component store corruption flags. RestoreHealth actively downloads or copies replacement files to repair the store—ScanHealth does not repair by itself.

Q.Why does DISM fail with 0x800f081f or source errors?

RestoreHealth could not obtain replacement payloads—common when Windows Update is blocked, the repair WIM build mismatches the OS, or the source path/index is wrong. Provide a correct /Source and verify index with dism /Get-WimInfo.

Q.Should I run DISM or SFC first?

If you suspect component store corruption or SFC cannot repair, run DISM /Online /Cleanup-Image /RestoreHealth first, reboot if needed, then run sfc /scannow.

Q.How long does DISM RestoreHealth take?

From minutes to well over an hour depending on disk speed, corruption extent, and whether files download from Windows Update. Plan on a maintenance window and stable power.

Q.Can DISM repair a PC that will not boot?

Boot Windows Recovery or WinPE, mount the offline Windows folder with DISM /Image:C:\offline … Cleanup-Image options, or apply a captured WIM per your deployment process.

Q.Where are DISM logs?

Primary DISM details live under %windir%\Logs\DISM\dism.log. Cross-check CBS.log for underlying component errors when results are unclear.

Q.Is DISM only for servers?

No. The same DISM servicing stack is used on Windows client SKUs for component repair, optional features, and image preparation—syntax scope differs by scenario, not audience.