"There Were Some Problems Installing Updates" 0x80073701? Repair the Missing Assembly

A cumulative or feature update fails with “There were some problems installing updates, but we’ll try again later” and the code 0x80073701.

Why: 0x80073701 is ERROR_SXS_ASSEMBLY_MISSING. Microsoft’s own diagnosis is that some system files are missing — the update package references a component (an “assembly”) in the component store (WinSxS) that isn’t there, so the install can’t complete. The fix is to repair the component store so the missing pieces are restored, not to keep retrying the same download.

Fix 1: Run the Windows Update troubleshooter

Start here — it resets the update components and clears the most common transient cases.

1. Select Start → Settings → System → Troubleshoot → Other troubleshooters.
2. Under Most frequent, select Run next to Windows Update.
3. Restart, then go to Settings → Windows Update → Check for updates.

Fix 2: Repair the component store with DISM and SFC

This is the core fix for a missing assembly. Open an elevated Command Prompt (search cmd and choose Run as administrator) and run, in order:

DISM /Online /Cleanup-Image /ScanHealth
DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

RestoreHealth pulls clean replacement files from Windows Update; sfc /scannow then repairs any protected system files. Restart and retry the update.

Fix 3: Repair from a matching Windows image (offline)

If RestoreHealth can’t reach Windows Update — or the store is too damaged to self-heal — give DISM a clean source:

1. Download the Windows ISO that matches your build (same version, e.g. 24H2) and mount it (assume it becomes D:).
2. Repair against it, blocking Windows Update so it uses your media:

   DISM /Online /Cleanup-Image /RestoreHealth /Source:ESD:D:\sources\install.esd:1 /LimitAccess

   For a WIM source, change both the prefix to WIM: and the filename to install.wim. Replace the drive and image index with the verified source for your edition, language, architecture and Windows version; a generic index 1 is not necessarily your edition. The source must have the required servicing files/update level.
3. Restart, run sfc /scannow, then retry the update.

Fix 4: Reset the update cache, then retry

If the store is now healthy but the package still won’t apply, clear the download cache. Elevated Command Prompt:

net stop wuauserv
net stop bits
net stop cryptsvc
ren %systemroot%\SoftwareDistribution SoftwareDistribution.old
ren %systemroot%\System32\catroot2 catroot2.old
net start wuauserv
net start bits
net start cryptsvc

Reboot and Check for updates.

These cache commands are for administrator Command Prompt in the installed Windows session. Save work first. If a service does not stop, a folder remains locked or the .old destination already exists, inspect the error before continuing; preserve existing backups. Restart stopped services afterward. Do not use these percent-variable commands from PowerShell or WinRE.

FAQ

Which file is actually missing? Open C:\Windows\Logs\CBS\CBS.log and search for ERROR_SXS_ASSEMBLY_MISSING — it names the package (a KB) and component. Advanced users can then reinstall that KB from the Microsoft Update Catalog.

Will a repair install fix it? Yes — running setup.exe from the matching ISO with “Keep personal files and apps” rebuilds the component store and is the dependable last resort if DISM with a source won’t.

Sources: Microsoft Learn — Stop Cryptographic Services before renaming catroot2, Microsoft Learn — How to resolve error 0x80073701 (ERROR_SXS_ASSEMBLY_MISSING), Microsoft Support — Troubleshoot problems updating Windows