Check C:\Windows\Logs\CBS\CBS.log for the missing KB (search for 0x800f0831), install that KB from the Microsoft Update Catalog, then retry. Also disable any VPN/proxy, reset the update cache and run DISM/SFC.

0x800F0831, explained

0x800F0831 is CBS_E_STORE_CORRUPTION: the servicing stack found that a package the new update depends on isn’t present in the expected state. The CBS log often names the package (KB number) it was looking for.

What you'll see

  • “Install error - 0x800f0831” for a cumulative update.
  • The same update fails again after each restart.
  • CBS.log lists a missing or corrupt package.

Common causes

  • A previous cumulative or servicing-stack update didn't install properly.
  • VPN or proxy interrupting downloads.
  • Corrupted component store.

How to fix it

  1. Find the missing packageOpen C:\Windows\Logs\CBS\CBS.log in Notepad and search for 0x800f0831. Note the KB number mentioned near it.
  2. Install it manuallyDownload that KB (correct version and architecture) from the Microsoft Update Catalog and install it, then retry the failing update.
  3. Turn off VPN and proxyDisconnect VPN software and disable manual proxies during updating.
  4. Reset cache and repairReset SoftwareDistribution/catroot2, then run DISM and SFC.
  5. In-place repair installIf it still fails, run setup from a matching Windows ISO and keep files and apps.

Command

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

Elevated Command Prompt; restart afterwards.

Check it's fixed: The cumulative update installs and Update history shows success.

Stop it happening again

Let servicing-stack and cumulative updates finish in order; avoid interrupting restarts.