0x80240034 WU_E_DOWNLOAD_FAILED: Fix Windows Update Download Error

Fix Windows Update error 0x80240034 (WU_E_DOWNLOAD_FAILED) in Windows 10 and 11 with easy steps: free up space, reset update cache, and install updates manually.

Windows Update error 0x80240034 (WU_E_DOWNLOAD_FAILED) means an update started downloading but could not finish. You usually see it when an update gets stuck at a percentage like 0% or 99% and then fails. The cause is usually a damaged update cache, low disk space, or a stopped update service. This guide explains why it happens and walks you through the fixes, from the quickest to the most thorough.

Quick answer: Free up at least 20 GB of disk space, reset the Windows Update cache (Fix 4), restart your PC, and check for updates again. If it still fails, download the update manually from the Microsoft Update Catalog (Fix 7).

What does error 0x80240034 mean?

The code 0x80240034 stands for WU_E_DOWNLOAD_FAILED, which simply means “Update failed to download.” Windows Update reached Microsoft’s servers, but the downloaded files were incomplete, damaged, or could not be saved.

You may see messages like:

• There were problems installing some updates... Download error - 0x80240034
• 2026-xx Cumulative Update for Windows 11... Download error - 0x80240034
• An update stuck at Downloading - 0% or 99% before failing

Common causes

• Corrupted update cache in the SoftwareDistribution folder
• Not enough free disk space for the update
• Windows Update or BITS service stopped or stuck
• Metered connection settings blocking downloads
• Damaged system files
• An unstable internet connection, VPN, or antivirus interfering with the download

How to fix error 0x80240034

Try the fixes in order. Restart your PC after each one and check Windows Update again.

Fix 1: Restart your PC and retry the update

A simple restart clears stuck downloads and restarts the update services.

1. Restart your PC (do not just shut down).
2. Go to Settings > Windows Update.
3. Select Check for updates or Retry.

Fix 2: Run the Windows Update troubleshooter

1. Open troubleshooter settings

   • Windows 11: Go to Settings > System > Troubleshoot > Other troubleshooters.
   • Windows 10: Go to Settings > Update & Security > Troubleshoot > Additional troubleshooters.
2. Run the Windows Update troubleshooter

   Select Run next to Windows Update and apply any fixes it suggests.

Fix 3: Free up disk space

Large feature updates need plenty of space to download and unpack.

1. Check free space

   Open File Explorer > This PC and check the free space on drive C:. Aim for at least 20 GB free.

2. Run Disk Cleanup

   Search Disk Cleanup in Start, choose drive C:, then select Clean up system files.

3. Delete old update files

   Check Windows Update Cleanup, Temporary files, and Delivery Optimization Files, then select OK.

On Windows 11, you can also use Settings > System > Storage > Cleanup recommendations to free space quickly.

Fix 4: Reset the Windows Update cache

This is the most effective fix for 0x80240034. It deletes the broken download so Windows can start fresh.

Open Command Prompt as administrator and run these commands one by one:

Reset Windows Update cache

net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 catroot2.old
net start wuauserv
net start cryptSvc
net start bits
net start msiserver

Restart your PC and check for updates.

Fix 5: Make sure update services are running

1. Open Services

   Press Win + R, type services.msc, and press Enter.

2. Check these services

   Find each service below, double-click it, set Startup type as shown, and select Start if it is stopped:

   • Windows Update: Manual (or Automatic)
   • Background Intelligent Transfer Service (BITS): Manual (or Automatic)
   • Cryptographic Services: Automatic
3. Apply and retry

   Select OK, then try Windows Update again.

Fix 6: Turn off metered connection, VPN, and antivirus

1. Go to Settings > Network & internet, open your Wi-Fi or Ethernet connection, and turn off Metered connection.
2. In Settings > Windows Update > Advanced options, turn on Download updates over metered connections if available.
3. Disconnect any VPN and temporarily pause third-party antivirus. Turn them back on after the update installs.

Fix 7: Install the update manually

If Windows Update keeps failing, download the update yourself.

1. Find the KB number

   Go to Settings > Windows Update (or Update history) and note the KB number of the failed update, for example KB5031455.

2. Open the Microsoft Update Catalog

   Visit the Microsoft Update Catalog and search for the KB number.

3. Download the right version

   Pick the version that matches your system (Windows 11 or 10, x64 or ARM64) and select Download.

4. Install it

   Double-click the downloaded .msu file and follow the prompts. Restart when asked.

Fix 8: Repair system files with DISM and SFC

Damaged system files can stop updates from downloading or installing correctly.

Open Command Prompt as administrator and run:

Repair system files

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

Wait for both scans to finish, restart your PC, and try again.

Fix 9: Use the Windows Installation Assistant

For large feature updates (such as a new Windows 11 version), Microsoft’s Installation Assistant can update your PC without Windows Update.

1. Go to Microsoft’s official Download Windows 11 page.
2. Under Windows 11 Installation Assistant, select Download Now.
3. Run the tool and follow the prompts. Your files and apps stay in place.

How to prevent error 0x80240034

• Keep at least 20 GB of free space on drive C:.
• Do not turn off your PC while updates are downloading.
• Avoid metered connections when big updates are due.
• Run Disk Cleanup every few months to remove old update files.

Frequently asked questions

What is WU_E_DOWNLOAD_FAILED?

It is the internal name for error 0x80240034. It means Windows Update could not finish downloading an update.

Why is my update stuck at 0% or 99% with 0x80240034?

The download is stuck because of a damaged update cache or a stopped service. Resetting the Windows Update cache (Fix 4) usually solves it.

Is it safe to delete the SoftwareDistribution folder?

Yes. It only stores temporary update files. Windows creates a fresh folder automatically. Renaming it, as shown in Fix 4, is the safest way.

Will fixing 0x80240034 delete my files?

No. None of these fixes remove your personal files or apps.

Does 0x80240034 happen on Windows 11?

Yes. It appears on both Windows 10 and Windows 11, and the same fixes work on both.