Windows Update stuck at 0%, 100%, or halfway

What you see: the update download or install freezes — Microsoft's own page covers "stuck at 0%, 100%, or 51–99%" — sometimes with an error code like 0x80240034. The ladder below is Microsoft's documented sequence, from the 30-second fix to the in-place reinstall. Stop at the first step that works.

Step 1 — Update and restart

Choose Start > Power > Update and restart and give it 10–15 minutes after reboot. Updates often finish installing in that window with no progress bar at all.

Step 2 — Run the Windows Update troubleshooter

1. Start > Settings > System > Troubleshoot > Other troubleshooters.
2. Under "Most frequent", next to Windows Update, select Run.
3. Restart your device when the troubleshooter finishes — Microsoft's instruction, and the part people skip.

Step 3 — Clear the update cache

The download cache corrupts more often than anything else:

1. Press Win+R, type services.msc, Enter.
2. Right-click Windows Update > Stop.
3. Delete the contents of C:\Windows\SoftwareDistribution.
4. Back in Services, start Windows Update again, then check for updates.

Advanced variant (admin Command Prompt) if that's not enough — rename the folders so Windows rebuilds them, then restart:

net stop bits
net stop wuauserv
ren %systemroot%\softwaredistribution softwaredistribution.bak
ren %systemroot%\system32\catroot2 catroot2.bak
net start bits
net start wuauserv

Also check free disk space: the 64-bit update needs about 20 GB free.

Step 4 — Repair Windows' own files

Run these two commands in an administrator Command Prompt, in this order, waiting for each to hit 100%:

DISM.exe /Online /Cleanup-image /Restorehealth
sfc /scannow

Then Settings > Windows Update > Check for updates again.

Step 5 — The in-place reinstall (last resort)

Start > Settings > System > Recovery > under "Fix problems using Windows Update" select Reinstall now. This reinstalls the current Windows over itself and — per Microsoft — "preserves your apps, files, and settings." (Requires Windows 11 22H2+ with the Feb 2024 update; hidden on managed/work devices.)

Still broken?

A clean install from Microsoft's software-download page is the documented final path — back up first. For repeated specific error codes, search the code on Microsoft Q&A, where the per-code fixes live.

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