Error codes

0x800F0826

Windows could not add the update

What it means

The update package started installing and then failed, usually after an earlier update or the servicing stack left the store half changed.

Common causes

• A previous update failed and left the store inconsistent
• The servicing stack is outdated
• Antivirus or a tweak tool blocked a file

How to fix it

1. Install the latest servicing stack update from the Microsoft Update Catalog first.
2. Reset the update cache: in Terminal (Admin) run net stop wuauserv, net stop bits, rename C:\Windows\SoftwareDistribution to SoftwareDistribution.old, then net start wuauserv and net start bits.
3. Open Terminal (Admin) and run sfc /scannow, then DISM /Online /Cleanup-Image /RestoreHealth. Restart afterwards.
4. If it still fails, do an in-place upgrade with the current Windows ISO and keep your files.